diff --git a/app/androidApp/src/main/assets/backdrops/pexels-bogdankrupin-12049700.jpg b/app/androidApp/src/main/assets/backdrops/pexels-bogdankrupin-12049700.jpg
new file mode 100644
index 0000000..dc460cb
Binary files /dev/null and b/app/androidApp/src/main/assets/backdrops/pexels-bogdankrupin-12049700.jpg differ
diff --git a/app/androidApp/src/main/assets/backdrops/pexels-bosichong-27940302.jpg b/app/androidApp/src/main/assets/backdrops/pexels-bosichong-27940302.jpg
new file mode 100644
index 0000000..87930cc
Binary files /dev/null and b/app/androidApp/src/main/assets/backdrops/pexels-bosichong-27940302.jpg differ
diff --git a/app/androidApp/src/main/assets/backdrops/pexels-farhan-najeer-644774196-32490483.jpg b/app/androidApp/src/main/assets/backdrops/pexels-farhan-najeer-644774196-32490483.jpg
new file mode 100644
index 0000000..9afb6f9
Binary files /dev/null and b/app/androidApp/src/main/assets/backdrops/pexels-farhan-najeer-644774196-32490483.jpg differ
diff --git a/app/androidApp/src/main/assets/backdrops/pexels-soubhagya23-8060218.jpg b/app/androidApp/src/main/assets/backdrops/pexels-soubhagya23-8060218.jpg
new file mode 100644
index 0000000..1651100
Binary files /dev/null and b/app/androidApp/src/main/assets/backdrops/pexels-soubhagya23-8060218.jpg differ
diff --git a/app/androidApp/src/main/assets/backdrops/pexels-steve-29390703.jpg b/app/androidApp/src/main/assets/backdrops/pexels-steve-29390703.jpg
new file mode 100644
index 0000000..99f1c88
Binary files /dev/null and b/app/androidApp/src/main/assets/backdrops/pexels-steve-29390703.jpg differ
diff --git a/app/androidApp/src/main/assets/backdrops/pexels-yunszyveli-12368637.jpg b/app/androidApp/src/main/assets/backdrops/pexels-yunszyveli-12368637.jpg
new file mode 100644
index 0000000..f8c3302
Binary files /dev/null and b/app/androidApp/src/main/assets/backdrops/pexels-yunszyveli-12368637.jpg differ
diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index f87a81d..89c69c9 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -23,4 +23,4 @@ plugins {
 
 tasks.register("clean") {
     delete(rootProject.layout.buildDirectory)
-}
\ No newline at end of file
+}
diff --git a/app/shared/build.gradle.kts b/app/shared/build.gradle.kts
index 12f42e8..045f69b 100644
--- a/app/shared/build.gradle.kts
+++ b/app/shared/build.gradle.kts
@@ -92,4 +92,4 @@ kotlin {
             implementation("com.google.firebase:firebase-messaging:25.1.2")
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/androidMain/kotlin/iris/platform/AndroidMedia.kt b/app/shared/src/androidMain/kotlin/iris/platform/AndroidMedia.kt
index 4471cfa..2a1a10c 100644
--- a/app/shared/src/androidMain/kotlin/iris/platform/AndroidMedia.kt
+++ b/app/shared/src/androidMain/kotlin/iris/platform/AndroidMedia.kt
@@ -40,16 +40,16 @@ import androidx.compose.ui.unit.sp
 import androidx.compose.ui.viewinterop.AndroidView
 import androidx.core.content.FileProvider
 import androidx.core.net.toUri
-import androidx.media3.common.MediaItem as M3MediaItem
 import androidx.media3.common.Player
 import androidx.media3.exoplayer.ExoPlayer
 import androidx.media3.ui.PlayerView
 import iris.data.MediaItem
 import iris.media.extForMime
 import iris.protocol.KIND_VIDEO
-import java.io.File
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
+import java.io.File
+import androidx.media3.common.MediaItem as M3MediaItem
 
 /** App context holder (set in MainActivity.onCreate). */
 object AndroidEnv {
@@ -59,24 +59,25 @@ object AndroidEnv {
 @Composable
 actual fun MediaFilePicker(onPicked: (PickedFile?) -> Unit) {
     val context = LocalContext.current
-    val launcher = rememberLauncherForActivityResult(ActivityResultContracts.GetContent()) { uri ->
-        if (uri == null) {
-            onPicked(null)
-            return@rememberLauncherForActivityResult
-        }
-        try {
-            val mime = context.contentResolver.getType(uri) ?: "application/octet-stream"
-            val name = queryDisplayName(context, uri) ?: "upload"
-            val dir = File(context.cacheDir, "uploads").apply { mkdirs() }
-            val target = File(dir, "${System.currentTimeMillis()}${extForMime(mime)}")
-            context.contentResolver.openInputStream(uri)!!.use { input ->
-                target.outputStream().use { output -> input.copyTo(output) }
+    val launcher =
+        rememberLauncherForActivityResult(ActivityResultContracts.GetContent()) { uri ->
+            if (uri == null) {
+                onPicked(null)
+                return@rememberLauncherForActivityResult
+            }
+            try {
+                val mime = context.contentResolver.getType(uri) ?: "application/octet-stream"
+                val name = queryDisplayName(context, uri) ?: "upload"
+                val dir = File(context.cacheDir, "uploads").apply { mkdirs() }
+                val target = File(dir, "${System.currentTimeMillis()}${extForMime(mime)}")
+                context.contentResolver.openInputStream(uri)!!.use { input ->
+                    target.outputStream().use { output -> input.copyTo(output) }
+                }
+                onPicked(PickedFile(target.absolutePath, name, mime, target.length()))
+            } catch (e: Exception) {
+                onPicked(null)
             }
-            onPicked(PickedFile(target.absolutePath, name, mime, target.length()))
-        } catch (e: Exception) {
-            onPicked(null)
         }
-    }
     Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
         Button(onClick = { launcher.launch("*/*") }) { Text("Pick a file") }
     }
@@ -85,29 +86,33 @@ actual fun MediaFilePicker(onPicked: (PickedFile?) -> Unit) {
 @Composable
 actual fun ImageFilePicker(onPicked: (PickedFile?) -> Unit) {
     val context = LocalContext.current
-    val launcher = rememberLauncherForActivityResult(ActivityResultContracts.GetContent()) { uri ->
-        if (uri == null) {
-            onPicked(null)
-            return@rememberLauncherForActivityResult
-        }
-        try {
-            val mime = context.contentResolver.getType(uri) ?: "image/jpeg"
-            val name = queryDisplayName(context, uri) ?: "background"
-            // Persistent (filesDir), unlike the upload staging dir in cacheDir.
-            val dir = File(context.filesDir, "theme").apply { mkdirs() }
-            val target = File(dir, "background${extForMime(mime)}")
-            context.contentResolver.openInputStream(uri)!!.use { input ->
-                target.outputStream().use { output -> input.copyTo(output) }
+    val launcher =
+        rememberLauncherForActivityResult(ActivityResultContracts.GetContent()) { uri ->
+            if (uri == null) {
+                onPicked(null)
+                return@rememberLauncherForActivityResult
+            }
+            try {
+                val mime = context.contentResolver.getType(uri) ?: "image/jpeg"
+                val name = queryDisplayName(context, uri) ?: "background"
+                // Persistent (filesDir), unlike the upload staging dir in cacheDir.
+                val dir = File(context.filesDir, "theme").apply { mkdirs() }
+                val target = File(dir, "background${extForMime(mime)}")
+                context.contentResolver.openInputStream(uri)!!.use { input ->
+                    target.outputStream().use { output -> input.copyTo(output) }
+                }
+                onPicked(PickedFile(target.absolutePath, name, mime, target.length()))
+            } catch (e: Exception) {
+                onPicked(null)
             }
-            onPicked(PickedFile(target.absolutePath, name, mime, target.length()))
-        } catch (e: Exception) {
-            onPicked(null)
         }
-    }
     Button(onClick = { launcher.launch("image/*") }) { Text("Choose image…") }
 }
 
-private fun queryDisplayName(context: Context, uri: Uri): String? {
+private fun queryDisplayName(
+    context: Context,
+    uri: Uri,
+): String? {
     context.contentResolver.query(uri, null, null, null, null)?.use { c ->
         val idx = c.getColumnIndex(OpenableColumns.DISPLAY_NAME)
         if (idx >= 0 && c.moveToFirst()) return c.getString(idx)
@@ -119,59 +124,99 @@ actual fun mediaCacheBaseDir(): String =
     AndroidEnv.context.externalCacheDir?.absolutePath
         ?: AndroidEnv.context.cacheDir.absolutePath
 
-actual suspend fun loadMediaImage(path: String): ImageBitmap? = withContext(Dispatchers.IO) {
-    try {
-        BitmapFactory.decodeFile(path)?.asImageBitmap()
-    } catch (e: Exception) {
-        null
+actual suspend fun loadMediaImage(path: String): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            BitmapFactory.decodeFile(path)?.asImageBitmap()
+        } catch (e: Exception) {
+            null
+        }
     }
-}
 
-actual suspend fun loadScaledImage(path: String, maxSize: Int): ImageBitmap? = withContext(Dispatchers.IO) {
-    try {
-        // inJustDecodeBounds fills [bounds] and returns null by design — only
-        // the outWidth/outHeight are meaningful here.
-        val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
-        BitmapFactory.decodeFile(path, bounds)
-        if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return@withContext null
-        var sample = 1
-        while (maxOf(bounds.outWidth, bounds.outHeight) / sample > maxSize) sample *= 2
-        val opts = BitmapFactory.Options().apply { inSampleSize = sample }
-        BitmapFactory.decodeFile(path, opts)?.asImageBitmap()
-    } catch (e: Exception) {
-        null
+actual suspend fun loadScaledImage(
+    path: String,
+    maxSize: Int,
+): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            // inJustDecodeBounds fills [bounds] and returns null by design — only
+            // the outWidth/outHeight are meaningful here.
+            val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+            BitmapFactory.decodeFile(path, bounds)
+            if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return@withContext null
+            var sample = 1
+            while (maxOf(bounds.outWidth, bounds.outHeight) / sample > maxSize) sample *= 2
+            val opts = BitmapFactory.Options().apply { inSampleSize = sample }
+            BitmapFactory.decodeFile(path, opts)?.asImageBitmap()
+        } catch (e: Exception) {
+            null
+        }
     }
-}
 
-actual suspend fun encodeImageAsBase64(path: String, maxSize: Int): String? = withContext(Dispatchers.IO) {
-    try {
-        val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
-        BitmapFactory.decodeFile(path, bounds)
-        if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return@withContext null
-        var sample = 1
-        while (maxOf(bounds.outWidth, bounds.outHeight) / sample > maxSize) sample *= 2
-        val opts = BitmapFactory.Options().apply { inSampleSize = sample }
-        val bitmap = BitmapFactory.decodeFile(path, opts) ?: return@withContext null
-        val stream = java.io.ByteArrayOutputStream()
-        bitmap.compress(android.graphics.Bitmap.CompressFormat.PNG, 100, stream)
-        bitmap.recycle()
-        android.util.Base64.encodeToString(stream.toByteArray(), android.util.Base64.NO_WRAP)
-    } catch (e: Exception) {
-        null
+actual suspend fun decodeImageBytes(
+    bytes: ByteArray,
+    maxSize: Int,
+): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+            BitmapFactory.decodeByteArray(bytes, 0, bytes.size, bounds)
+            if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return@withContext null
+            var sample = 1
+            while (maxOf(bounds.outWidth, bounds.outHeight) / sample > maxSize) sample *= 2
+            val opts = BitmapFactory.Options().apply { inSampleSize = sample }
+            BitmapFactory.decodeByteArray(bytes, 0, bytes.size, opts)?.asImageBitmap()
+        } catch (e: Exception) {
+            null
+        }
     }
-}
 
-actual suspend fun decodeBase64Image(base64: String): ImageBitmap? = withContext(Dispatchers.IO) {
+actual fun readBackdropBytes(id: String): ByteArray? =
     try {
-        val bytes = android.util.Base64.decode(base64, android.util.Base64.DEFAULT)
-        BitmapFactory.decodeByteArray(bytes, 0, bytes.size)?.asImageBitmap()
+        AndroidEnv.context.assets
+            .open("backdrops/$id.jpg")
+            .use { it.readBytes() }
     } catch (e: Exception) {
         null
     }
-}
+
+actual suspend fun encodeImageAsBase64(
+    path: String,
+    maxSize: Int,
+): String? =
+    withContext(Dispatchers.IO) {
+        try {
+            val bounds = BitmapFactory.Options().apply { inJustDecodeBounds = true }
+            BitmapFactory.decodeFile(path, bounds)
+            if (bounds.outWidth <= 0 || bounds.outHeight <= 0) return@withContext null
+            var sample = 1
+            while (maxOf(bounds.outWidth, bounds.outHeight) / sample > maxSize) sample *= 2
+            val opts = BitmapFactory.Options().apply { inSampleSize = sample }
+            val bitmap = BitmapFactory.decodeFile(path, opts) ?: return@withContext null
+            val stream = java.io.ByteArrayOutputStream()
+            bitmap.compress(android.graphics.Bitmap.CompressFormat.PNG, 100, stream)
+            bitmap.recycle()
+            android.util.Base64.encodeToString(stream.toByteArray(), android.util.Base64.NO_WRAP)
+        } catch (e: Exception) {
+            null
+        }
+    }
+
+actual suspend fun decodeBase64Image(base64: String): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            val bytes = android.util.Base64.decode(base64, android.util.Base64.DEFAULT)
+            BitmapFactory.decodeByteArray(bytes, 0, bytes.size)?.asImageBitmap()
+        } catch (e: Exception) {
+            null
+        }
+    }
 
 @Composable
-actual fun MediaPlayerView(media: MediaItem, modifier: Modifier) {
+actual fun MediaPlayerView(
+    media: MediaItem,
+    modifier: Modifier,
+) {
     val path = media.localPath
     if (path == null) {
         Box(modifier = modifier, contentAlignment = Alignment.Center) {
@@ -191,7 +236,10 @@ actual fun MediaPlayerView(media: MediaItem, modifier: Modifier) {
 }
 
 @Composable
-private fun VideoPlayerView(path: String, modifier: Modifier) {
+private fun VideoPlayerView(
+    path: String,
+    modifier: Modifier,
+) {
     AndroidView(
         factory = { ctx ->
             PlayerView(ctx).apply {
@@ -205,21 +253,27 @@ private fun VideoPlayerView(path: String, modifier: Modifier) {
         },
         update = {},
         onRelease = { view -> view.player?.release() },
-        modifier = modifier
-            .fillMaxWidth()
-            .height(220.dp),
+        modifier =
+            modifier
+                .fillMaxWidth()
+                .height(220.dp),
     )
 }
 
 @Composable
-private fun AudioPlayerView(path: String, filename: String, modifier: Modifier) {
+private fun AudioPlayerView(
+    path: String,
+    filename: String,
+    modifier: Modifier,
+) {
     val context = LocalContext.current
-    val player = remember {
-        ExoPlayer.Builder(context).build().apply {
-            setMediaItem(M3MediaItem.fromUri(path.toUri()))
-            prepare()
+    val player =
+        remember {
+            ExoPlayer.Builder(context).build().apply {
+                setMediaItem(M3MediaItem.fromUri(path.toUri()))
+                prepare()
+            }
         }
-    }
     DisposableEffect(player) { onDispose { player.release() } }
 
     var playing by remember { mutableStateOf(false) }
@@ -237,9 +291,10 @@ private fun AudioPlayerView(path: String, filename: String, modifier: Modifier)
     }
 
     Row(
-        modifier = modifier
-            .fillMaxWidth()
-            .padding(8.dp),
+        modifier =
+            modifier
+                .fillMaxWidth()
+                .padding(8.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
         IconButton(onClick = {
@@ -270,17 +325,21 @@ private fun fmt(seconds: Float): String {
     return "%d:%02d".format(s / 60, s % 60)
 }
 
-actual fun openDocument(path: String, mime: String) {
+actual fun openDocument(
+    path: String,
+    mime: String,
+) {
     val context = AndroidEnv.context
     try {
         val file = File(path)
         val uri = FileProvider.getUriForFile(context, "${context.packageName}.fileprovider", file)
-        val intent = Intent(Intent.ACTION_VIEW).apply {
-            setDataAndType(uri, mime)
-            addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
-        }
+        val intent =
+            Intent(Intent.ACTION_VIEW).apply {
+                setDataAndType(uri, mime)
+                addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION)
+            }
         context.startActivity(intent)
     } catch (e: Exception) {
-        Toast.makeText(context, "No app to open ${mime}", Toast.LENGTH_SHORT).show()
+        Toast.makeText(context, "No app to open $mime", Toast.LENGTH_SHORT).show()
     }
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/androidMain/kotlin/iris/platform/AndroidSecureStore.kt b/app/shared/src/androidMain/kotlin/iris/platform/AndroidSecureStore.kt
index 42474cb..32b4582 100644
--- a/app/shared/src/androidMain/kotlin/iris/platform/AndroidSecureStore.kt
+++ b/app/shared/src/androidMain/kotlin/iris/platform/AndroidSecureStore.kt
@@ -6,6 +6,8 @@ import android.os.Build
 import androidx.security.crypto.EncryptedSharedPreferences
 import androidx.security.crypto.MasterKey
 import iris.data.SecureStore
+import iris.ui.theme.Backdrop
+import iris.ui.theme.BackgroundMode
 import iris.ui.theme.UserTheme
 import java.util.UUID
 
@@ -15,18 +17,22 @@ import java.util.UUID
  * values are migrated on first run (read old key, write encrypted, delete
  * old key) so an upgrade never loses the pairing.
  */
-class AndroidSecureStore(context: Context) : SecureStore {
+class AndroidSecureStore(
+    context: Context,
+) : SecureStore {
     private val appContext = context.applicationContext
     private val plainPrefs = appContext.getSharedPreferences(PLAIN_PREFS_NAME, Context.MODE_PRIVATE)
-    private val prefs: SharedPreferences = EncryptedSharedPreferences.create(
-        appContext,
-        SECURE_PREFS_NAME,
-        MasterKey.Builder(appContext)
-            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
-            .build(),
-        EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
-        EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM,
-    )
+    private val prefs: SharedPreferences =
+        EncryptedSharedPreferences.create(
+            appContext,
+            SECURE_PREFS_NAME,
+            MasterKey
+                .Builder(appContext)
+                .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+                .build(),
+            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM,
+        )
 
     init {
         migratePlainValues()
@@ -50,7 +56,8 @@ class AndroidSecureStore(context: Context) : SecureStore {
         }
         if (migrated) editor.apply()
         // The plain store must not keep a copy of any value.
-        plainPrefs.edit()
+        plainPrefs
+            .edit()
             .remove(KEY_URL)
             .remove(KEY_TOKEN)
             .remove(KEY_DEVICE_ID)
@@ -73,7 +80,12 @@ class AndroidSecureStore(context: Context) : SecureStore {
         get() {
             var id = prefs.getString(KEY_DEVICE_ID, null)
             if (id.isNullOrBlank()) {
-                id = "dev_" + UUID.randomUUID().toString().replace("-", "").take(16)
+                id = "dev_" +
+                    UUID
+                        .randomUUID()
+                        .toString()
+                        .replace("-", "")
+                        .take(16)
                 prefs.edit().putString(KEY_DEVICE_ID, id).apply()
             }
             return id
@@ -123,7 +135,11 @@ class AndroidSecureStore(context: Context) : SecureStore {
         set(value) = prefs.edit().putInt(KEY_AGENT_BUBBLE_COLOR, value).apply()
 
     override var backgroundMode: String
-        get() = prefs.getString(KEY_BACKGROUND_MODE, "color").orEmpty().ifBlank { "color" }
+        get() =
+            prefs
+                .getString(KEY_BACKGROUND_MODE, BackgroundMode.Image.name.lowercase())
+                .orEmpty()
+                .ifBlank { BackgroundMode.Image.name.lowercase() }
         set(value) = prefs.edit().putString(KEY_BACKGROUND_MODE, value).apply()
 
     override var backgroundColor: Int
@@ -131,20 +147,31 @@ class AndroidSecureStore(context: Context) : SecureStore {
         set(value) = prefs.edit().putInt(KEY_BACKGROUND_COLOR, value).apply()
 
     override var backgroundImagePath: String
-        get() = prefs.getString(KEY_BACKGROUND_IMAGE_PATH, "").orEmpty()
+        get() =
+            prefs
+                .getString(KEY_BACKGROUND_IMAGE_PATH, Backdrop.DEFAULT.path)
+                .orEmpty()
+                .ifBlank { Backdrop.DEFAULT.path }
         set(value) = prefs.edit().putString(KEY_BACKGROUND_IMAGE_PATH, value).apply()
 
     override var fontSizeScale: Float
         get() = prefs.getFloat(KEY_FONT_SIZE_SCALE, 1.0f)
         set(value) = prefs.edit().putFloat(KEY_FONT_SIZE_SCALE, value).apply()
 
-    override fun savePairing(url: String, token: String) {
+    override fun savePairing(
+        url: String,
+        token: String,
+    ) {
         serverUrl = url
         this.token = token
     }
 
     override fun clear() {
-        prefs.edit().remove(KEY_URL).remove(KEY_TOKEN).apply()
+        prefs
+            .edit()
+            .remove(KEY_URL)
+            .remove(KEY_TOKEN)
+            .apply()
     }
 
     private companion object {
@@ -168,4 +195,4 @@ class AndroidSecureStore(context: Context) : SecureStore {
         const val KEY_BACKGROUND_IMAGE_PATH = "background_image_path"
         const val KEY_FONT_SIZE_SCALE = "font_size_scale"
     }
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/androidMain/kotlin/iris/platform/Platform.kt b/app/shared/src/androidMain/kotlin/iris/platform/Platform.kt
index d8b8dfd..90e1282 100644
--- a/app/shared/src/androidMain/kotlin/iris/platform/Platform.kt
+++ b/app/shared/src/androidMain/kotlin/iris/platform/Platform.kt
@@ -1,3 +1,3 @@
 package iris.platform
 
-actual val isDesktop: Boolean = false
\ No newline at end of file
+actual val isDesktop: Boolean = false
diff --git a/app/shared/src/commonMain/kotlin/iris/platform/Platform.kt b/app/shared/src/commonMain/kotlin/iris/platform/Platform.kt
index 2506f06..5a0fb21 100644
--- a/app/shared/src/commonMain/kotlin/iris/platform/Platform.kt
+++ b/app/shared/src/commonMain/kotlin/iris/platform/Platform.kt
@@ -1,4 +1,4 @@
 package iris.platform
 
 /** True on the desktop target (M6: big-screen layout, shortcuts, tray). */
-expect val isDesktop: Boolean
\ No newline at end of file
+expect val isDesktop: Boolean
diff --git a/app/shared/src/commonMain/kotlin/iris/platform/PlatformMedia.kt b/app/shared/src/commonMain/kotlin/iris/platform/PlatformMedia.kt
index 654b3a1..0bc9174 100644
--- a/app/shared/src/commonMain/kotlin/iris/platform/PlatformMedia.kt
+++ b/app/shared/src/commonMain/kotlin/iris/platform/PlatformMedia.kt
@@ -35,21 +35,49 @@ expect fun mediaCacheBaseDir(): String
 expect suspend fun loadMediaImage(path: String): ImageBitmap?
 
 /** Load an image scaled to at most [maxSize] px on the longest edge. Null on failure. */
-expect suspend fun loadScaledImage(path: String, maxSize: Int): ImageBitmap?
+expect suspend fun loadScaledImage(
+    path: String,
+    maxSize: Int,
+): ImageBitmap?
+
+/**
+ * Decode an image from raw bytes (bundled backdrops), scaled to at most
+ * [maxSize] px on the longest edge. Null on failure.
+ */
+expect suspend fun decodeImageBytes(
+    bytes: ByteArray,
+    maxSize: Int,
+): ImageBitmap?
+
+/**
+ * Read a bundled backdrop image (shipped in the app) by its [id] (the file
+ * name without extension, e.g. `pexels-yunszyveli-12368637`). Android reads it
+ * from `assets/backdrops/`, desktop from the classpath. Null on failure.
+ */
+expect fun readBackdropBytes(id: String): ByteArray?
 
 /**
  * Encode a local image as a base64 PNG, downscaled to at most [maxSize] px on
  * the longest edge. Null on failure. Used for channel icons (stored on the
  * gateway, synced across devices).
  */
-expect suspend fun encodeImageAsBase64(path: String, maxSize: Int): String?
+expect suspend fun encodeImageAsBase64(
+    path: String,
+    maxSize: Int,
+): String?
 
 /** Decode a base64-encoded image (PNG/JPEG) into an [ImageBitmap]. Null on failure. */
 expect suspend fun decodeBase64Image(base64: String): ImageBitmap?
 
 /** Inline audio/video player (ExoPlayer on Android; placeholder on desktop). */
 @Composable
-expect fun MediaPlayerView(media: MediaItem, modifier: Modifier)
+expect fun MediaPlayerView(
+    media: MediaItem,
+    modifier: Modifier,
+)
 
 /** Open a document with the system handler (best effort). */
-expect fun openDocument(path: String, mime: String)
\ No newline at end of file
+expect fun openDocument(
+    path: String,
+    mime: String,
+)
diff --git a/app/shared/src/commonMain/kotlin/iris/state/IrisController.kt b/app/shared/src/commonMain/kotlin/iris/state/IrisController.kt
index fcc5656..c552cc9 100644
--- a/app/shared/src/commonMain/kotlin/iris/state/IrisController.kt
+++ b/app/shared/src/commonMain/kotlin/iris/state/IrisController.kt
@@ -1,7 +1,7 @@
 package iris.state
 
-import iris.data.ChatStore
 import iris.data.ChannelStore
+import iris.data.ChatStore
 import iris.data.MediaItem
 import iris.data.MessageItem
 import iris.data.MsgStatus
@@ -24,22 +24,21 @@ import iris.protocol.MessageDeletedPayload
 import iris.protocol.MessagePayload
 import iris.protocol.MessageStopPayload
 import iris.protocol.NotificationPayload
-import iris.protocol.ReadReceiptPayload
 import iris.protocol.ROLE_ASSISTANT
+import iris.protocol.ReadReceiptPayload
 import iris.protocol.SearchHit
 import iris.protocol.SearchResultsPayload
 import iris.protocol.SlashCommand
 import iris.protocol.StatusPayload
 import iris.protocol.SyncDonePayload
-import iris.protocol.TYPE_ERROR
-import iris.protocol.TYPE_HISTORY
-import iris.protocol.TYPE_NOTIFICATION
 import iris.protocol.TYPE_CHANNEL_CREATED
 import iris.protocol.TYPE_CHANNEL_DELETED
 import iris.protocol.TYPE_CHANNEL_LIST
 import iris.protocol.TYPE_CHANNEL_RENAMED
 import iris.protocol.TYPE_COMMANDS_CATALOG
 import iris.protocol.TYPE_COMMENTARY
+import iris.protocol.TYPE_ERROR
+import iris.protocol.TYPE_HISTORY
 import iris.protocol.TYPE_MEDIA_OFFER
 import iris.protocol.TYPE_MESSAGE
 import iris.protocol.TYPE_MESSAGE_DELETE
@@ -47,6 +46,7 @@ import iris.protocol.TYPE_MESSAGE_DELETED
 import iris.protocol.TYPE_MESSAGE_START
 import iris.protocol.TYPE_MESSAGE_STOP
 import iris.protocol.TYPE_MESSAGE_UPDATE
+import iris.protocol.TYPE_NOTIFICATION
 import iris.protocol.TYPE_READ_RECEIPT
 import iris.protocol.TYPE_SEARCH_RESULTS
 import iris.protocol.TYPE_STATUS
@@ -69,6 +69,7 @@ import iris.protocol.historyFrame
 import iris.protocol.messageDeleteFrame
 import iris.protocol.searchFrame
 import iris.protocol.syncFrame
+import iris.ui.theme.Backdrop
 import iris.ui.theme.BackgroundMode
 import iris.ui.theme.UserTheme
 import kotlinx.coroutines.CoroutineScope
@@ -105,11 +106,12 @@ class IrisController(
     val toolDetail: StateFlow<ToolDetail> = _toolDetail.asStateFlow()
 
     fun cycleToolDetail() {
-        _toolDetail.value = when (_toolDetail.value) {
-            ToolDetail.EVERYTHING -> ToolDetail.TRUNCATED
-            ToolDetail.TRUNCATED -> ToolDetail.NOTHING
-            ToolDetail.NOTHING -> ToolDetail.EVERYTHING
-        }
+        _toolDetail.value =
+            when (_toolDetail.value) {
+                ToolDetail.EVERYTHING -> ToolDetail.TRUNCATED
+                ToolDetail.TRUNCATED -> ToolDetail.NOTHING
+                ToolDetail.NOTHING -> ToolDetail.EVERYTHING
+            }
         store.toolDetail = _toolDetail.value.name.lowercase()
     }
 
@@ -170,17 +172,19 @@ class IrisController(
     // ── Appearance (Settings → Appearance) ────────────────────────────────
     // User-customizable bubble colors + background (color or image).
     // Persisted as ARGB ints + an image path (see UserTheme).
-    private val _theme = MutableStateFlow(
-        UserTheme(
-            userBubbleColor = store.userBubbleColor,
-            agentBubbleColor = store.agentBubbleColor,
-            backgroundMode = BackgroundMode.entries.firstOrNull {
-                it.name.equals(store.backgroundMode, ignoreCase = true)
-            } ?: BackgroundMode.Color,
-            backgroundColor = store.backgroundColor,
-            backgroundImagePath = store.backgroundImagePath.ifBlank { null },
+    private val _theme =
+        MutableStateFlow(
+            UserTheme(
+                userBubbleColor = store.userBubbleColor,
+                agentBubbleColor = store.agentBubbleColor,
+                backgroundMode =
+                    BackgroundMode.entries.firstOrNull {
+                        it.name.equals(store.backgroundMode, ignoreCase = true)
+                    } ?: BackgroundMode.Color,
+                backgroundColor = store.backgroundColor,
+                backgroundImagePath = store.backgroundImagePath.ifBlank { null },
+            ),
         )
-    )
     val theme: StateFlow<UserTheme> = _theme.asStateFlow()
 
     fun setUserBubbleColor(argb: Int) = updateTheme { it.copy(userBubbleColor = argb) }
@@ -189,13 +193,25 @@ class IrisController(
 
     fun setBackgroundColor(argb: Int) = updateTheme { it.copy(backgroundColor = argb) }
 
-    fun setBackgroundMode(mode: BackgroundMode) = updateTheme { it.copy(backgroundMode = mode) }
+    fun setBackgroundMode(mode: BackgroundMode) =
+        updateTheme {
+            // Switching to image mode without an image falls back to the default
+            // bundled backdrop instead of silently showing the solid color.
+            it.copy(
+                backgroundMode = mode,
+                backgroundImagePath =
+                    if (mode == BackgroundMode.Image && it.backgroundImagePath.isNullOrBlank()) {
+                        Backdrop.DEFAULT.path
+                    } else {
+                        it.backgroundImagePath
+                    },
+            )
+        }
 
     fun setBackgroundImagePath(path: String?) = updateTheme { it.copy(backgroundImagePath = path) }
 
     /** Clears the background image and falls back to the solid color. */
-    fun removeBackgroundImage() =
-        updateTheme { it.copy(backgroundImagePath = null, backgroundMode = BackgroundMode.Color) }
+    fun removeBackgroundImage() = updateTheme { it.copy(backgroundImagePath = null, backgroundMode = BackgroundMode.Color) }
 
     fun resetTheme() = updateTheme { UserTheme() }
 
@@ -261,6 +277,7 @@ class IrisController(
     val attachments: StateFlow<List<PendingAttachment>> = _attachments.asStateFlow()
 
     // ── M5: notification banners (docs/08 §8.3) ───────────────────────────
+
     /** An in-app notification banner shown above the composer. */
     data class Banner(
         val id: Long,
@@ -280,7 +297,13 @@ class IrisController(
         _banners.value = _banners.value.filterNot { it.id == id }
     }
 
-    private fun pushBanner(kind: String, title: String, body: String, chatId: String?, threadId: String?) {
+    private fun pushBanner(
+        kind: String,
+        title: String,
+        body: String,
+        chatId: String?,
+        threadId: String?,
+    ) {
         val persistent = kind in HIGH_PRIORITY_NOTIF_KINDS
         val banner = Banner(bannerSeq++, kind, title, body, chatId, threadId, persistent)
         _banners.value = (_banners.value + banner).takeLast(5)
@@ -299,7 +322,11 @@ class IrisController(
      * the chat (deep link). The same per-chat notification id is reused, so a
      * multi-segment turn updates one notification instead of stacking.
      */
-    private fun notifyMessageIfBackgrounded(chatId: String?, threadId: String?, text: String) {
+    private fun notifyMessageIfBackgrounded(
+        chatId: String?,
+        threadId: String?,
+        text: String,
+    ) {
         if (isAppForeground()) return
         if (text.isBlank()) return
         val id = chatId ?: "android:default"
@@ -308,7 +335,10 @@ class IrisController(
     }
 
     /** Single-line preview for a notification body (lock-screen privacy). */
-    private fun preview(text: String, limit: Int = 120): String {
+    private fun preview(
+        text: String,
+        limit: Int = 120,
+    ): String {
         val flat = text.replace('\n', ' ').replace('\t', ' ').trim()
         return if (flat.length <= limit) flat else flat.take(limit).trimEnd() + "…"
     }
@@ -318,7 +348,10 @@ class IrisController(
 
     /** Open the chat referenced by a push notification tap. Applied now if
      *  connected, otherwise on the next hello.ack (lane may not exist yet). */
-    fun openDeepLink(chatId: String?, threadId: String?) {
+    fun openDeepLink(
+        chatId: String?,
+        threadId: String?,
+    ) {
         if (chatId.isNullOrBlank()) return
         pendingDeepLink = chatId to threadId
         if (client.state.value is GatewayClient.State.Connected) applyDeepLink()
@@ -343,7 +376,8 @@ class IrisController(
                     TYPE_TOOL_PROGRESS,
                     TYPE_TOOL_END,
                     TYPE_COMMENTARY,
-                    TYPE_MEDIA_OFFER -> {
+                    TYPE_MEDIA_OFFER,
+                    -> {
                         chat.onFrame(frame)
                         // M4: pull offered media into the local cache.
                         if (frame.type == TYPE_MEDIA_OFFER) {
@@ -356,23 +390,31 @@ class IrisController(
                         // message.stop; non-streaming replies are a single
                         // assistant `message`.
                         when (frame.type) {
-                            TYPE_MESSAGE_STOP ->
+                            TYPE_MESSAGE_STOP -> {
                                 frame.payloadAs<MessageStopPayload>()?.let {
                                     notifyMessageIfBackgrounded(frame.chatId, frame.threadId, it.finalText)
                                 }
-                            TYPE_MESSAGE ->
+                            }
+
+                            TYPE_MESSAGE -> {
                                 frame.payloadAs<MessagePayload>()?.let {
                                     if (it.role == ROLE_ASSISTANT) {
                                         notifyMessageIfBackgrounded(frame.chatId, frame.threadId, it.text)
                                     }
                                 }
-                            else -> Unit
+                            }
+
+                            else -> {
+                                Unit
+                            }
                         }
                     }
+
                     TYPE_CHANNEL_CREATED,
                     TYPE_CHANNEL_RENAMED,
                     TYPE_CHANNEL_DELETED,
-                    TYPE_CHANNEL_LIST -> {
+                    TYPE_CHANNEL_LIST,
+                    -> {
                         channels.onFrame(frame)
                         // Auto-created thread (Settings → "Threads"): the
                         // gateway minted it for a message in the flat lane we
@@ -396,26 +438,37 @@ class IrisController(
                             frame.payloadAs<ChannelDeletedPayload>()?.let { p ->
                                 val (curChat, curThread) = chat.parseLane(chat.currentLane.value)
                                 when {
-                                    curThread == p.chatId -> openChannel(curChat)
-                                    curChat == p.chatId ->
+                                    curThread == p.chatId -> {
+                                        openChannel(curChat)
+                                    }
+
+                                    curChat == p.chatId -> {
                                         channels.defaultChannel()?.let { openChannel(it.chatId) }
-                                    else -> Unit
+                                    }
+
+                                    else -> {
+                                        Unit
+                                    }
                                 }
                             }
                         }
                     }
+
                     TYPE_SEARCH_RESULTS -> {
                         frame.payloadAs<SearchResultsPayload>()?.let { _searchResults.value = it.hits }
                         _searching.value = false
                     }
+
                     TYPE_COMMANDS_CATALOG -> {
                         frame.payloadAs<CommandsCatalogPayload>()?.let { _slashCommands.value = it.commands }
                     }
+
                     TYPE_SYNC_DONE -> {
                         // Replayed frames already flowed through [events]; the
                         // cursor is authoritative server-side (outbox).
                         frame.payloadAs<SyncDonePayload>()?.let { store.syncCursor = it.cursor }
                     }
+
                     TYPE_HISTORY -> {
                         // Full message history for a chat/thread (initial open /
                         // restart restore). `sync` only replays the outbox delta
@@ -432,6 +485,7 @@ class IrisController(
                             )
                         }
                     }
+
                     TYPE_NOTIFICATION -> {
                         frame.payloadAs<NotificationPayload>()?.let { p ->
                             pushBanner(p.kind, p.title, p.body, p.chatId, p.threadId)
@@ -444,12 +498,15 @@ class IrisController(
                             }
                         }
                     }
+
                     TYPE_TYPING -> {
                         frame.payloadAs<TypingPayload>()?.let { _typing.value = it.on }
                     }
+
                     TYPE_READ_RECEIPT -> {
                         frame.payloadAs<ReadReceiptPayload>()?.let { chat.markRead(it.messageId) }
                     }
+
                     TYPE_MESSAGE_DELETED -> {
                         // A message was deleted (by this or another device).
                         // Idempotent: dropping an unknown id is a no-op.
@@ -457,16 +514,21 @@ class IrisController(
                             chat.removeMessages(it.messageIds.toSet())
                         }
                     }
+
                     TYPE_STATUS -> {
                         frame.payloadAs<StatusPayload>()?.let { _gatewayStatus.value = it.state }
                     }
+
                     TYPE_ERROR -> {
                         // M7: error frames are global, not per-message — fail
                         // any optimistic sends still in flight so they don't
                         // sit at "sending…" forever.
                         chat.failPending()
                     }
-                    else -> Unit
+
+                    else -> {
+                        Unit
+                    }
                 }
             }
         }
@@ -537,7 +599,10 @@ class IrisController(
 
     /** Switch to a specific thread lane under [chatId]. Loads the full history
      *  on first open this session. */
-    fun openThread(chatId: String, threadId: String) {
+    fun openThread(
+        chatId: String,
+        threadId: String,
+    ) {
         chat.setLane(chat.laneKey(chatId, threadId))
         loadHistory(chatId, threadId)
     }
@@ -550,13 +615,19 @@ class IrisController(
         client.sendFrame(channelCreateFrame(0, trimmed))
     }
 
-    fun createThread(name: String, parentChatId: String) {
+    fun createThread(
+        name: String,
+        parentChatId: String,
+    ) {
         val trimmed = name.trim()
         if (trimmed.isEmpty()) return
         client.sendFrame(channelCreateFrame(0, trimmed, kind = "thread", parentChatId = parentChatId))
     }
 
-    fun renameChannel(chatId: String, name: String) {
+    fun renameChannel(
+        chatId: String,
+        name: String,
+    ) {
         val trimmed = name.trim()
         if (trimmed.isEmpty()) return
         client.sendFrame(channelRenameFrame(0, chatId, trimmed))
@@ -567,19 +638,29 @@ class IrisController(
     }
 
     /** Toggle the cosmetic favorite flag (sorts the channel to the top). */
-    fun setChannelFavorite(chatId: String, on: Boolean) {
+    fun setChannelFavorite(
+        chatId: String,
+        on: Boolean,
+    ) {
         client.sendFrame(channelFavoriteFrame(0, chatId, on))
     }
 
     /** Mark the channel as automation (read-only; cron/webhook output only).
      *  The default channel cannot be marked (the server enforces this too). */
-    fun setChannelAutomation(chatId: String, on: Boolean) {
+    fun setChannelAutomation(
+        chatId: String,
+        on: Boolean,
+    ) {
         client.sendFrame(channelSetAutomationFrame(0, chatId, on))
     }
 
     /** Set the channel's cosmetic icon (base64 image) and/or avatar color.
      *  Pass null to clear a field. */
-    fun setChannelIcon(chatId: String, icon: String?, color: String?) {
+    fun setChannelIcon(
+        chatId: String,
+        icon: String?,
+        color: String?,
+    ) {
         client.sendFrame(channelIconFrame(0, chatId, icon, color))
     }
 
@@ -593,7 +674,12 @@ class IrisController(
 
     // ── M3: search ────────────────────────────────────────────────────────
 
-    fun search(query: String, scope: String = "all", chatId: String? = null, threadId: String? = null) {
+    fun search(
+        query: String,
+        scope: String = "all",
+        chatId: String? = null,
+        threadId: String? = null,
+    ) {
         val q = query.trim()
         if (q.isEmpty()) return
         _lastQuery.value = q
@@ -626,7 +712,10 @@ class IrisController(
      *  Populates the lane via the `history` response; used on first open of a
      *  chat and after a process death (restart) to restore the view, since the
      *  `sync` delta does not cover messages older than the saved cursor. */
-    fun loadHistory(chatId: String, threadId: String? = null) {
+    fun loadHistory(
+        chatId: String,
+        threadId: String? = null,
+    ) {
         val lane = chat.laneKey(chatId, threadId)
         if (lane in historyLoaded) return
         historyLoaded.add(lane)
@@ -636,20 +725,27 @@ class IrisController(
     }
 
     /** Optimistic send: show immediately in the current lane, then hand to the gateway.
- *  M4: [attachments] (uploaded) are attached via media_refs. */
-    fun send(text: String, attachments: List<PendingAttachment> = emptyList()) {
+     *  M4: [attachments] (uploaded) are attached via media_refs. */
+    fun send(
+        text: String,
+        attachments: List<PendingAttachment> = emptyList(),
+    ) {
         val trimmed = text.trim()
         val refs = attachments.mapNotNull { it.mediaRef }
         if (trimmed.isEmpty() && refs.isEmpty()) return
         val lane = chat.currentLane.value
         val (chatId, threadId) = chat.parseLane(lane)
-        val media = attachments.map {
-            MediaItem(
-                mediaId = it.mediaRef ?: it.filename,
-                kind = it.kind, mime = it.mime, size = it.size, filename = it.filename,
-                localPath = it.path,
-            )
-        }
+        val media =
+            attachments.map {
+                MediaItem(
+                    mediaId = it.mediaRef ?: it.filename,
+                    kind = it.kind,
+                    mime = it.mime,
+                    size = it.size,
+                    filename = it.filename,
+                    localPath = it.path,
+                )
+            }
         chat.addPending(trimmed, lane, media)
         client.sendMessage(chatId, trimmed, threadId, refs, autoThread = wantsAutoThread(trimmed, threadId, chatId))
         _attachments.value = emptyList()
@@ -660,7 +756,11 @@ class IrisController(
      *  gateway (Telegram topic-mode workflow). Threading is only active on
      *  the default channel; other channels stay flat. Slash commands and
      *  media-only sends stay in the flat lane. */
-    private fun wantsAutoThread(text: String, threadId: String?, chatId: String): Boolean =
+    private fun wantsAutoThread(
+        text: String,
+        threadId: String?,
+        chatId: String,
+    ): Boolean =
         _threadsEnabled.value &&
             threadId == null &&
             text.isNotEmpty() &&
@@ -700,28 +800,36 @@ class IrisController(
     /** Stage a picked file: upload it, then keep it as a pending attachment. */
     fun attachFile(picked: PickedFile) {
         val kind = kindFromMime(picked.mime)
-        val placeholder = PendingAttachment(
-            filename = picked.name, mime = picked.mime, size = picked.size, kind = kind,
-            path = picked.path,
-        )
+        val placeholder =
+            PendingAttachment(
+                filename = picked.name,
+                mime = picked.mime,
+                size = picked.size,
+                kind = kind,
+                path = picked.path,
+            )
         _attachments.value = _attachments.value + placeholder
         scope.launch {
             val mediaRef = "up_${Random.nextLong(1_000_000_000L, 9_999_999_999L)}"
-            val result = client.uploadMedia(
-                path = picked.path,
-                mime = picked.mime,
-                kind = kind,
-                filename = picked.name,
-                mediaRef = mediaRef,
-            )
-            _attachments.value = _attachments.value.map {
-                if (it.filename == picked.name && it.uploading) {
-                    result.fold(
-                        { ref -> it.copy(uploading = false, mediaRef = ref) },
-                        { e -> it.copy(uploading = false, error = e.message) },
-                    )
-                } else it
-            }
+            val result =
+                client.uploadMedia(
+                    path = picked.path,
+                    mime = picked.mime,
+                    kind = kind,
+                    filename = picked.name,
+                    mediaRef = mediaRef,
+                )
+            _attachments.value =
+                _attachments.value.map {
+                    if (it.filename == picked.name && it.uploading) {
+                        result.fold(
+                            { ref -> it.copy(uploading = false, mediaRef = ref) },
+                            { e -> it.copy(uploading = false, error = e.message) },
+                        )
+                    } else {
+                        it
+                    }
+                }
         }
     }
 
@@ -748,7 +856,10 @@ class IrisController(
     }
 
     /** Connect-screen action: real hello test, then save + (re)connect. */
-    suspend fun connect(url: String, token: String): Result<Unit> {
+    suspend fun connect(
+        url: String,
+        token: String,
+    ): Result<Unit> {
         val test = client.testHello(url, token)
         if (test.isFailure) return test
         store.savePairing(url, token)
@@ -779,9 +890,10 @@ private fun HistoryMessage.toMessageItem(): MessageItem =
         reasoning = reasoning,
         model = model,
         tokens = tokens,
-        media = media.map {
-            MediaItem(mediaId = it.mediaId, kind = it.kind, mime = it.mime, size = it.size, filename = it.filename)
-        },
+        media =
+            media.map {
+                MediaItem(mediaId = it.mediaId, kind = it.kind, mime = it.mime, size = it.size, filename = it.filename)
+            },
     )
 
 // Gateway restart routine (hermes, same icon + wording on all platforms). The
@@ -797,14 +909,13 @@ private const val GATEWAY_ONLINE_MSG =
 
 /** How much tool detail to show (Settings → "Tool detail"). */
 enum class ToolDetail {
-    EVERYTHING,   // name + full args (collapsible) + output preview
-    TRUNCATED,    // one-liner "emoji name: preview", collapsible (default)
-    NOTHING,      // suppress tool cards entirely
+    EVERYTHING, // name + full args (collapsible) + output preview
+    TRUNCATED, // one-liner "emoji name: preview", collapsible (default)
+    NOTHING, // suppress tool cards entirely
     ;
 
     companion object {
         /** Parse a persisted value; unknown/blank falls back to the default. */
-        fun fromName(name: String): ToolDetail =
-            entries.firstOrNull { it.name.equals(name, ignoreCase = true) } ?: TRUNCATED
+        fun fromName(name: String): ToolDetail = entries.firstOrNull { it.name.equals(name, ignoreCase = true) } ?: TRUNCATED
     }
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/commonMain/kotlin/iris/ui/screens/ChatScreen.kt b/app/shared/src/commonMain/kotlin/iris/ui/screens/ChatScreen.kt
index aa56925..f1f56da 100644
--- a/app/shared/src/commonMain/kotlin/iris/ui/screens/ChatScreen.kt
+++ b/app/shared/src/commonMain/kotlin/iris/ui/screens/ChatScreen.kt
@@ -10,6 +10,7 @@ import androidx.compose.animation.fadeOut
 import androidx.compose.animation.slideInVertically
 import androidx.compose.animation.slideOutVertically
 import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.Image
 import androidx.compose.foundation.background
 import androidx.compose.foundation.border
 import androidx.compose.foundation.clickable
@@ -23,6 +24,7 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.PaddingValues
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
@@ -31,8 +33,6 @@ import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.widthIn
-import androidx.compose.foundation.Image
-import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.lazy.LazyColumn
 import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.lazy.rememberLazyListState
@@ -72,8 +72,8 @@ import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
-import androidx.compose.runtime.snapshotFlow
 import androidx.compose.runtime.setValue
+import androidx.compose.runtime.snapshotFlow
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
@@ -268,14 +268,18 @@ fun ChatScreen(controller: IrisController) {
     val slashCommands by controller.slashCommands.collectAsState()
     val slashQuery =
         if (input.startsWith("/") && !input.contains(" ")) input.removePrefix("/") else null
-    val slashMatches = remember(slashQuery, slashCommands) {
-        if (slashQuery == null) emptyList()
-        else slashCommands
-            .map { it to bestSlashScore(slashQuery, it) }
-            .filter { it.second >= 0 }
-            .sortedWith(compareBy({ it.second }, { it.first.name }))
-            .map { it.first }
-    }
+    val slashMatches =
+        remember(slashQuery, slashCommands) {
+            if (slashQuery == null) {
+                emptyList()
+            } else {
+                slashCommands
+                    .map { it to bestSlashScore(slashQuery, it) }
+                    .filter { it.second >= 0 }
+                    .sortedWith(compareBy({ it.second }, { it.first.name }))
+                    .map { it.first }
+            }
+        }
     val slashDrawerOpen = slashQuery != null && slashMatches.isNotEmpty()
 
     // The catalog is fetched on connect; if the drawer opens before the first
@@ -292,46 +296,71 @@ fun ChatScreen(controller: IrisController) {
     }
 
     // M6: keyboard shortcuts (docs/11 §11.3) — desktop only.
-    val shortcutsModifier = if (isDesktop) {
-        Modifier.onPreviewKeyEvent { e ->
-            if (e.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
-            val ctrlOrMeta = e.isCtrlPressed || e.isMetaPressed
-            val overlayOpen =
-                showSearch || showPicker || showPalette || showNewChannel || showNewThread || showSettings
-            when {
-                ctrlOrMeta && e.key == Key.N -> { showNewChannel = true; true }
-                // Threads are only active on the default channel.
-                ctrlOrMeta && e.key == Key.T -> {
-                    if (currentChannel?.isDefault == true) showNewThread = true
-                    true
+    val shortcutsModifier =
+        if (isDesktop) {
+            Modifier.onPreviewKeyEvent { e ->
+                if (e.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
+                val ctrlOrMeta = e.isCtrlPressed || e.isMetaPressed
+                val overlayOpen =
+                    showSearch || showPicker || showPalette || showNewChannel || showNewThread || showSettings
+                when {
+                    ctrlOrMeta && e.key == Key.N -> {
+                        showNewChannel = true
+                        true
+                    }
+
+                    // Threads are only active on the default channel.
+                    ctrlOrMeta && e.key == Key.T -> {
+                        if (currentChannel?.isDefault == true) showNewThread = true
+                        true
+                    }
+
+                    ctrlOrMeta && e.key == Key.F -> {
+                        showSearch = true
+                        true
+                    }
+
+                    ctrlOrMeta && e.key == Key.K -> {
+                        showPalette = true
+                        true
+                    }
+
+                    // Escape closes the slash drawer (clears the "/" input).
+                    e.key == Key.Escape && slashDrawerOpen -> {
+                        input = ""
+                        true
+                    }
+
+                    e.key == Key.Escape && overlayOpen -> {
+                        showSearch = false
+                        showPicker = false
+                        showPalette = false
+                        showNewChannel = false
+                        showNewThread = false
+                        showSettings = false
+                        true
+                    }
+
+                    e.key == Key.Slash && !composerFocused && !overlayOpen -> {
+                        composerFocusRequester.requestFocus()
+                        true
+                    }
+
+                    else -> {
+                        false
+                    }
                 }
-                ctrlOrMeta && e.key == Key.F -> { showSearch = true; true }
-                ctrlOrMeta && e.key == Key.K -> { showPalette = true; true }
-                // Escape closes the slash drawer (clears the "/" input).
-                e.key == Key.Escape && slashDrawerOpen -> { input = ""; true }
-                e.key == Key.Escape && overlayOpen -> {
-                    showSearch = false
-                    showPicker = false
-                    showPalette = false
-                    showNewChannel = false
-                    showNewThread = false
-                    showSettings = false
-                    true
-                }
-                e.key == Key.Slash && !composerFocused && !overlayOpen -> {
-                    composerFocusRequester.requestFocus()
-                    true
-                }
-                else -> false
             }
+        } else {
+            Modifier
         }
-    } else {
-        Modifier
-    }
 
     // M6: the chat column (header + list + composer), shared by both layouts.
     @Composable
-    fun ChatContent(showHamburger: Boolean, onOpenDrawer: () -> Unit) {
+    fun ChatContent(
+        showHamburger: Boolean,
+        onOpenDrawer: () -> Unit,
+    ) {
         // Topic context menu (long-press / right-click): rename / delete a thread.
         var renameThread by remember { mutableStateOf<ChannelInfo?>(null) }
         var deleteThread by remember { mutableStateOf<ChannelInfo?>(null) }
@@ -372,9 +401,10 @@ fun ChatScreen(controller: IrisController) {
             // Header: title pill on the left, status bubble + search on the
             // right, single row on both wide and narrow layouts.
             Row(
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .padding(horizontal = 8.dp, vertical = 6.dp),
+                modifier =
+                    Modifier
+                        .fillMaxWidth()
+                        .padding(horizontal = 8.dp, vertical = 6.dp),
                 verticalAlignment = Alignment.CenterVertically,
             ) {
                 if (showHamburger) {
@@ -396,12 +426,12 @@ fun ChatScreen(controller: IrisController) {
                 if (isDesktop) {
                     IconButton(onClick = { showInspector = !showInspector }) {
                         Box(
-                            modifier = Modifier
-                                .clip(RoundedCornerShape(8.dp))
-                                .background(
-                                    if (showInspector) IrisColors.chipSelected else Color.Transparent,
-                                )
-                                .padding(2.dp),
+                            modifier =
+                                Modifier
+                                    .clip(RoundedCornerShape(8.dp))
+                                    .background(
+                                        if (showInspector) IrisColors.chipSelected else Color.Transparent,
+                                    ).padding(2.dp),
                         ) {
                             Text("ⓘ", fontSize = 16.sp)
                         }
@@ -445,34 +475,45 @@ fun ChatScreen(controller: IrisController) {
                     }
                     items(rows, key = { it.key }) { row ->
                         when (row) {
-                            is ChatRow.Day -> DaySeparator(row.label)
-                            is ChatRow.Item -> when (val item = row.item) {
-                                is MessageItem -> {
-                                    if (item.isSystem) {
-                                        SystemMessage(item)
-                                    } else {
-                                        // Only finalized messages are selectable: a
-                                        // streaming bubble has no final id yet and a
-                                        // pending echo isn't on the server to delete.
-                                        val selectable = !item.streaming && !item.pending
-                                        MessageBubble(
-                                            msg = item,
-                                            maxWidth = bubbleMaxWidth,
-                                            reasoningAutoCollapse = reasoningAutoCollapse,
-                                            onRetry = { controller.retrySend(item.id) },
-                                            selectionMode = selectionMode && selectable,
-                                            selected = selectable && item.id in selectedIds,
-                                            onToggleSelect = { if (selectable) toggleSelect(item.id) },
-                                            onLongPress = {
-                                                if (selectable) {
-                                                    if (selectionMode) toggleSelect(item.id)
-                                                    else enterSelection(item.id)
-                                                }
-                                            },
-                                        )
+                            is ChatRow.Day -> {
+                                DaySeparator(row.label)
+                            }
+
+                            is ChatRow.Item -> {
+                                when (val item = row.item) {
+                                    is MessageItem -> {
+                                        if (item.isSystem) {
+                                            SystemMessage(item)
+                                        } else {
+                                            // Only finalized messages are selectable: a
+                                            // streaming bubble has no final id yet and a
+                                            // pending echo isn't on the server to delete.
+                                            val selectable = !item.streaming && !item.pending
+                                            MessageBubble(
+                                                msg = item,
+                                                maxWidth = bubbleMaxWidth,
+                                                reasoningAutoCollapse = reasoningAutoCollapse,
+                                                onRetry = { controller.retrySend(item.id) },
+                                                selectionMode = selectionMode && selectable,
+                                                selected = selectable && item.id in selectedIds,
+                                                onToggleSelect = { if (selectable) toggleSelect(item.id) },
+                                                onLongPress = {
+                                                    if (selectable) {
+                                                        if (selectionMode) {
+                                                            toggleSelect(item.id)
+                                                        } else {
+                                                            enterSelection(item.id)
+                                                        }
+                                                    }
+                                                },
+                                            )
+                                        }
+                                    }
+
+                                    is ToolItem -> {
+                                        if (toolDetail != ToolDetail.NOTHING) ToolCard(item, toolDetail)
                                     }
                                 }
-                                is ToolItem -> if (toolDetail != ToolDetail.NOTHING) ToolCard(item, toolDetail)
                             }
                         }
                     }
@@ -495,20 +536,21 @@ fun ChatScreen(controller: IrisController) {
                     val alpha = remember { Animatable(0f) }
                     LaunchedEffect(Unit) { alpha.animateTo(1f, tween(150)) }
                     Box(
-                        modifier = Modifier
-                            .align(Alignment.BottomEnd)
-                            .padding(end = 16.dp, bottom = 12.dp)
-                            .alpha(alpha.value)
-                            .size(40.dp)
-                            .clip(CircleShape)
-                            .background(IrisColors.surface)
-                            .border(1.dp, IrisColors.divider, CircleShape)
-                            .clickable {
-                                val last = listState.layoutInfo.totalItemsCount - 1
-                                if (last >= 0) {
-                                    drawerScope.launch { listState.animateScrollToItem(last) }
-                                }
-                            },
+                        modifier =
+                            Modifier
+                                .align(Alignment.BottomEnd)
+                                .padding(end = 16.dp, bottom = 12.dp)
+                                .alpha(alpha.value)
+                                .size(40.dp)
+                                .clip(CircleShape)
+                                .background(IrisColors.surface)
+                                .border(1.dp, IrisColors.divider, CircleShape)
+                                .clickable {
+                                    val last = listState.layoutInfo.totalItemsCount - 1
+                                    if (last >= 0) {
+                                        drawerScope.launch { listState.animateScrollToItem(last) }
+                                    }
+                                },
                         contentAlignment = Alignment.Center,
                     ) {
                         Icon(
@@ -524,10 +566,11 @@ fun ChatScreen(controller: IrisController) {
             // Pending attachments (M4; hidden in automation channels — no composer)
             if (attachments.isNotEmpty() && !isAutomation) {
                 Row(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .horizontalScroll(rememberScrollState())
-                        .padding(horizontal = 12.dp, vertical = 4.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .horizontalScroll(rememberScrollState())
+                            .padding(horizontal = 12.dp, vertical = 4.dp),
                     horizontalArrangement = Arrangement.spacedBy(6.dp),
                 ) {
                     attachments.forEach { att ->
@@ -539,9 +582,10 @@ fun ChatScreen(controller: IrisController) {
             // M5: notification banners (above the composer)
             if (banners.isNotEmpty()) {
                 Column(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(horizontal = 12.dp, vertical = 4.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 12.dp, vertical = 4.dp),
                     verticalArrangement = Arrangement.spacedBy(6.dp),
                 ) {
                     banners.forEach { b ->
@@ -559,28 +603,42 @@ fun ChatScreen(controller: IrisController) {
 
             // M7: connection-state banner (persistent, above the composer; no dismiss).
             val gatewayStatus by controller.gatewayStatus.collectAsState()
-            val connBanner = when {
-                state is GatewayClient.State.Connecting ->
-                    "Connecting to gateway…"
-                state is GatewayClient.State.Reconnecting ->
-                    "Reconnecting to gateway… messages will sync automatically when the connection is back."
-                gatewayStatus == "restarting" -> "Gateway is restarting…"
-                gatewayStatus == "degraded" ->
-                    "Gateway reports a degraded state — replies may be slow or unavailable."
-                else -> null
-            }
+            val connBanner =
+                when {
+                    state is GatewayClient.State.Connecting -> {
+                        "Connecting to gateway…"
+                    }
+
+                    state is GatewayClient.State.Reconnecting -> {
+                        "Reconnecting to gateway… messages will sync automatically when the connection is back."
+                    }
+
+                    gatewayStatus == "restarting" -> {
+                        "Gateway is restarting…"
+                    }
+
+                    gatewayStatus == "degraded" -> {
+                        "Gateway reports a degraded state — replies may be slow or unavailable."
+                    }
+
+                    else -> {
+                        null
+                    }
+                }
             if (connBanner != null) {
                 Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(horizontal = 12.dp, vertical = 4.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 12.dp, vertical = 4.dp),
                     contentAlignment = Alignment.Center,
                 ) {
                     Box(
-                        modifier = Modifier
-                            .clip(RoundedCornerShape(16.dp))
-                            .background(IrisColors.panel)
-                            .padding(horizontal = 14.dp, vertical = 8.dp),
+                        modifier =
+                            Modifier
+                                .clip(RoundedCornerShape(16.dp))
+                                .background(IrisColors.panel)
+                                .padding(horizontal = 14.dp, vertical = 8.dp),
                     ) {
                         Text(connBanner, fontSize = 12.sp, color = IrisColors.textTertiary)
                     }
@@ -596,27 +654,30 @@ fun ChatScreen(controller: IrisController) {
                 exit = fadeOut(tween(100)) + slideOutVertically(tween(120)) { it / 3 },
             ) {
                 Column(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(horizontal = 12.dp)
-                        .clip(RoundedCornerShape(16.dp))
-                        .background(IrisColors.panel)
-                        .border(1.dp, IrisColors.divider, RoundedCornerShape(16.dp)),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 12.dp)
+                            .clip(RoundedCornerShape(16.dp))
+                            .background(IrisColors.panel)
+                            .border(1.dp, IrisColors.divider, RoundedCornerShape(16.dp)),
                 ) {
                     slashMatches.take(SLASH_DRAWER_MAX).forEachIndexed { index, cmd ->
                         if (index > 0) {
                             Box(
-                                modifier = Modifier
-                                    .fillMaxWidth()
-                                    .height(1.dp)
-                                    .background(IrisColors.divider),
+                                modifier =
+                                    Modifier
+                                        .fillMaxWidth()
+                                        .height(1.dp)
+                                        .background(IrisColors.divider),
                             )
                         }
                         Row(
-                            modifier = Modifier
-                                .fillMaxWidth()
-                                .clickable { onSlashPick(cmd) }
-                                .padding(horizontal = 12.dp, vertical = 8.dp),
+                            modifier =
+                                Modifier
+                                    .fillMaxWidth()
+                                    .clickable { onSlashPick(cmd) }
+                                    .padding(horizontal = 12.dp, vertical = 8.dp),
                             verticalAlignment = Alignment.CenterVertically,
                         ) {
                             Column(modifier = Modifier.weight(1f)) {
@@ -668,16 +729,18 @@ fun ChatScreen(controller: IrisController) {
             if (isAutomation) {
                 // Read-only notice in place of the composer.
                 Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .padding(horizontal = 12.dp, vertical = 8.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 12.dp, vertical = 8.dp),
                     contentAlignment = Alignment.Center,
                 ) {
                     Box(
-                        modifier = Modifier
-                            .clip(RoundedCornerShape(16.dp))
-                            .background(IrisColors.panel)
-                            .padding(horizontal = 14.dp, vertical = 8.dp),
+                        modifier =
+                            Modifier
+                                .clip(RoundedCornerShape(16.dp))
+                                .background(IrisColors.panel)
+                                .padding(horizontal = 14.dp, vertical = 8.dp),
                     ) {
                         Text(
                             "⚙ Automation channel — read-only. Hermes posts cron/webhook output here; direct messages are not allowed.",
@@ -686,64 +749,70 @@ fun ChatScreen(controller: IrisController) {
                         )
                     }
                 }
-            } else if (!selectionMode) Row(
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .padding(horizontal = 12.dp, vertical = 8.dp)
-                    .clip(RoundedCornerShape(28.dp))
-                    .background(IrisColors.surface)
-                    .padding(horizontal = 6.dp, vertical = 4.dp),
-                verticalAlignment = Alignment.CenterVertically,
-            ) {
+            } else if (!selectionMode) {
                 Row(
-                    modifier = Modifier
-                        .weight(1f)
-                        .padding(horizontal = 6.dp, vertical = 10.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .padding(horizontal = 12.dp, vertical = 8.dp)
+                            .clip(RoundedCornerShape(28.dp))
+                            .background(IrisColors.surface)
+                            .padding(horizontal = 6.dp, vertical = 4.dp),
                     verticalAlignment = Alignment.CenterVertically,
                 ) {
-                    Box(modifier = Modifier.weight(1f)) {
-                        BasicTextField(
-                            value = input,
-                            onValueChange = { input = it },
-                            modifier = Modifier
-                                .fillMaxWidth()
-                                .heightIn(max = if (textHeightPx > 0f) (textHeightPx / layoutDensity).dp else Dp.Unspecified)
-                                .focusRequester(composerFocusRequester)
-                                .onFocusChanged { composerFocused = it.isFocused },
-                            textStyle = MaterialTheme.typography.bodyLarge.copy(color = IrisColors.onSurface),
-                            keyboardOptions = KeyboardOptions(imeAction = ImeAction.Send),
-                            keyboardActions = KeyboardActions(onSend = { doSend() }),
-                            onTextLayout = { result ->
-                                if (result.lineCount > 0) {
-                                    val totalHeight = result.getLineBottom(result.lineCount - 1)
-                                    val lineHeight = totalHeight / result.lineCount
-                                    textHeightPx = minOf(totalHeight, lineHeight * 5f)
-                                }
-                            },
-                        )
-                        if (input.isEmpty()) {
-                            Text(
-                                "Message",
-                                color = IrisColors.textDim,
-                                style = MaterialTheme.typography.bodyLarge,
-                                modifier = Modifier.align(Alignment.TopStart),
+                    Row(
+                        modifier =
+                            Modifier
+                                .weight(1f)
+                                .padding(horizontal = 6.dp, vertical = 10.dp),
+                        verticalAlignment = Alignment.CenterVertically,
+                    ) {
+                        Box(modifier = Modifier.weight(1f)) {
+                            BasicTextField(
+                                value = input,
+                                onValueChange = { input = it },
+                                modifier =
+                                    Modifier
+                                        .fillMaxWidth()
+                                        .heightIn(max = if (textHeightPx > 0f) (textHeightPx / layoutDensity).dp else Dp.Unspecified)
+                                        .focusRequester(composerFocusRequester)
+                                        .onFocusChanged { composerFocused = it.isFocused },
+                                textStyle = MaterialTheme.typography.bodyLarge.copy(color = IrisColors.onSurface),
+                                keyboardOptions = KeyboardOptions(imeAction = ImeAction.Send),
+                                keyboardActions = KeyboardActions(onSend = { doSend() }),
+                                onTextLayout = { result ->
+                                    if (result.lineCount > 0) {
+                                        val totalHeight = result.getLineBottom(result.lineCount - 1)
+                                        val lineHeight = totalHeight / result.lineCount
+                                        textHeightPx = minOf(totalHeight, lineHeight * 5f)
+                                    }
+                                },
                             )
+                            if (input.isEmpty()) {
+                                Text(
+                                    "Message",
+                                    color = IrisColors.textDim,
+                                    style = MaterialTheme.typography.bodyLarge,
+                                    modifier = Modifier.align(Alignment.TopStart),
+                                )
+                            }
+                        }
+                        IconButton(onClick = { showPicker = true }) {
+                            Text("📎", fontSize = 18.sp)
                         }
                     }
-                    IconButton(onClick = { showPicker = true }) {
-                        Text("📎", fontSize = 18.sp)
+                    Box(
+                        modifier =
+                            Modifier
+                                .size(40.dp)
+                                .clip(CircleShape)
+                                .background(if (canSend) IrisColors.primary else IrisColors.primary.copy(alpha = 0.35f))
+                                .clickable(enabled = canSend) { doSend() },
+                        contentAlignment = Alignment.Center,
+                    ) {
+                        Text("➤", color = Color.White, fontSize = 16.sp)
                     }
                 }
-                Box(
-                    modifier = Modifier
-                        .size(40.dp)
-                        .clip(CircleShape)
-                        .background(if (canSend) IrisColors.primary else IrisColors.primary.copy(alpha = 0.35f))
-                        .clickable(enabled = canSend) { doSend() },
-                    contentAlignment = Alignment.Center,
-                ) {
-                    Text("➤", color = Color.White, fontSize = 16.sp)
-                }
             }
 
             // Topic context menu: rename a thread.
@@ -786,8 +855,11 @@ fun ChatScreen(controller: IrisController) {
                     title = { Text(if (n == 1) "Delete message?" else "Delete $n messages?") },
                     text = {
                         Text(
-                            if (n == 1) "This message will be deleted for all devices."
-                            else "These messages will be deleted for all devices.",
+                            if (n == 1) {
+                                "This message will be deleted for all devices."
+                            } else {
+                                "These messages will be deleted for all devices."
+                            },
                         )
                     },
                     confirmButton = {
@@ -913,8 +985,11 @@ fun ChatScreen(controller: IrisController) {
             currentChatId = currentChatId,
             currentThreadId = currentThreadId,
             onJump = { hit ->
-                if (hit.threadId.isNullOrBlank()) controller.openChannel(hit.chatId)
-                else controller.openThread(hit.chatId, hit.threadId)
+                if (hit.threadId.isNullOrBlank()) {
+                    controller.openChannel(hit.chatId)
+                } else {
+                    controller.openThread(hit.chatId, hit.threadId)
+                }
                 showSearch = false
             },
             onDismiss = { showSearch = false },
@@ -1023,15 +1098,16 @@ fun ChatScreen(controller: IrisController) {
     // M6: command palette (Ctrl/Cmd+K)
     if (showPalette) {
         CommandPalette(
-            actions = listOf(
-                "new-channel" to "New channel (Ctrl+N)",
-                "new-thread" to "New topic (Ctrl+T)",
-                "search" to "Search (Ctrl+F)",
-                "toggle-threads" to "Toggle threads",
-                "toggle-reasoning-collapse" to "Toggle reasoning auto-collapse",
-                "cycle-tool-detail" to "Cycle tool verbosity",
-                "toggle-inspector" to "Toggle inspector",
-            ),
+            actions =
+                listOf(
+                    "new-channel" to "New channel (Ctrl+N)",
+                    "new-thread" to "New topic (Ctrl+T)",
+                    "search" to "Search (Ctrl+F)",
+                    "toggle-threads" to "Toggle threads",
+                    "toggle-reasoning-collapse" to "Toggle reasoning auto-collapse",
+                    "cycle-tool-detail" to "Cycle tool verbosity",
+                    "toggle-inspector" to "Toggle inspector",
+                ),
             onAction = { id ->
                 when (id) {
                     "new-channel" -> showNewChannel = true
@@ -1053,11 +1129,16 @@ fun ChatScreen(controller: IrisController) {
 private sealed interface ChatRow {
     val key: String
 
-    data class Item(val item: ChatItem) : ChatRow {
+    data class Item(
+        val item: ChatItem,
+    ) : ChatRow {
         override val key: String get() = item.id
     }
 
-    data class Day(val day: String, val label: String) : ChatRow {
+    data class Day(
+        val day: String,
+        val label: String,
+    ) : ChatRow {
         override val key: String get() = "day_$day"
     }
 }
@@ -1085,10 +1166,11 @@ private fun buildChatRows(items: List<ChatItem>): List<ChatRow> {
 private fun DaySeparator(label: String) {
     Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
         Box(
-            modifier = Modifier
-                .clip(RoundedCornerShape(12.dp))
-                .background(IrisColors.panel)
-                .padding(horizontal = 12.dp, vertical = 4.dp),
+            modifier =
+                Modifier
+                    .clip(RoundedCornerShape(12.dp))
+                    .background(IrisColors.panel)
+                    .padding(horizontal = 12.dp, vertical = 4.dp),
         ) {
             Text(label, fontSize = 12.sp, color = IrisColors.textSecondary)
         }
@@ -1102,10 +1184,11 @@ private fun DaySeparator(label: String) {
 private fun SystemMessage(msg: MessageItem) {
     Box(modifier = Modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
         Box(
-            modifier = Modifier
-                .clip(RoundedCornerShape(12.dp))
-                .background(IrisColors.panel)
-                .padding(horizontal = 12.dp, vertical = 6.dp),
+            modifier =
+                Modifier
+                    .clip(RoundedCornerShape(12.dp))
+                    .background(IrisColors.panel)
+                    .padding(horizontal = 12.dp, vertical = 6.dp),
         ) {
             Text(msg.text, fontSize = 12.sp, color = IrisColors.textSecondary)
         }
@@ -1126,21 +1209,24 @@ private fun TitlePill(
     val chatId = channel?.chatId
     val isAutomation = channel?.automation == true
     Box(
-        modifier = modifier
-            .clip(RoundedCornerShape(16.dp))
-            .background(IrisColors.surface)
-            .then(
-                if (isAutomation) {
-                    Modifier.clickable { chatId?.let(onCopyChatId) }
-                } else {
-                    Modifier
-                }
-            )
-            .padding(start = 8.dp, end = 12.dp, top = 4.dp, bottom = 4.dp),
+        modifier =
+            modifier
+                .clip(RoundedCornerShape(16.dp))
+                .background(IrisColors.surface)
+                .then(
+                    if (isAutomation) {
+                        Modifier.clickable { chatId?.let(onCopyChatId) }
+                    } else {
+                        Modifier
+                    },
+                ).padding(start = 8.dp, end = 12.dp, top = 4.dp, bottom = 4.dp),
     ) {
         Row(verticalAlignment = Alignment.CenterVertically) {
-            if (channel != null) ChannelAvatar(channel, 34.dp)
-            else LetterAvatar(channelName, 34.dp, IrisColors.primary)
+            if (channel != null) {
+                ChannelAvatar(channel, 34.dp)
+            } else {
+                LetterAvatar(channelName, 34.dp, IrisColors.primary)
+            }
             Spacer(modifier = Modifier.width(10.dp))
             Column {
                 Text(
@@ -1166,12 +1252,16 @@ private fun TitlePill(
 
 /** M7: compact 36dp header icon button (smaller than the 48dp default). */
 @Composable
-internal fun HeaderIconButton(onClick: () -> Unit, content: @Composable () -> Unit) {
+internal fun HeaderIconButton(
+    onClick: () -> Unit,
+    content: @Composable () -> Unit,
+) {
     Box(
-        modifier = Modifier
-            .size(36.dp)
-            .clip(RoundedCornerShape(10.dp))
-            .clickable(onClick = onClick),
+        modifier =
+            Modifier
+                .size(36.dp)
+                .clip(RoundedCornerShape(10.dp))
+                .clickable(onClick = onClick),
         contentAlignment = Alignment.Center,
     ) {
         content()
@@ -1180,13 +1270,23 @@ internal fun HeaderIconButton(onClick: () -> Unit, content: @Composable () -> Un
 
 /** M7: circle with the first letter of [name] (header / rail / drawer). */
 @Composable
-private fun LetterAvatar(name: String, size: Dp, color: Color) {
-    val letter = name.trim().firstOrNull()?.uppercaseChar()?.toString() ?: "?"
+private fun LetterAvatar(
+    name: String,
+    size: Dp,
+    color: Color,
+) {
+    val letter =
+        name
+            .trim()
+            .firstOrNull()
+            ?.uppercaseChar()
+            ?.toString() ?: "?"
     Box(
-        modifier = Modifier
-            .size(size)
-            .clip(CircleShape)
-            .background(color),
+        modifier =
+            Modifier
+                .size(size)
+                .clip(CircleShape)
+                .background(color),
         contentAlignment = Alignment.Center,
     ) {
         Text(
@@ -1210,7 +1310,10 @@ private fun parseHexColor(hex: String): Color {
  * tinted with the custom color (or the auto-generated name-hash color).
  */
 @Composable
-private fun ChannelAvatar(channel: ChannelInfo, size: Dp) {
+private fun ChannelAvatar(
+    channel: ChannelInfo,
+    size: Dp,
+) {
     if (channel.icon != null) {
         IconImage(channel.icon, size)
     } else {
@@ -1221,16 +1324,20 @@ private fun ChannelAvatar(channel: ChannelInfo, size: Dp) {
 
 /** Decodes a base64 channel-icon image and shows it (circular crop). */
 @Composable
-private fun IconImage(base64: String, size: Dp) {
+private fun IconImage(
+    base64: String,
+    size: Dp,
+) {
     var bitmap by remember(base64) { mutableStateOf<ImageBitmap?>(null) }
     LaunchedEffect(base64) {
         bitmap = decodeBase64Image(base64)
     }
     Box(
-        modifier = Modifier
-            .size(size)
-            .clip(CircleShape)
-            .background(IrisColors.panel),
+        modifier =
+            Modifier
+                .size(size)
+                .clip(CircleShape)
+                .background(IrisColors.panel),
         contentAlignment = Alignment.Center,
     ) {
         bitmap?.let {
@@ -1299,32 +1406,60 @@ private fun ChannelContextMenu(
 ) {
     val hasIcon = ch.icon != null || ch.color != null
     DropdownMenu(expanded = expanded, onDismissRequest = onDismiss) {
-        DropdownMenuItem(text = { Text("Rename") }, onClick = { onDismiss(); onRename() })
+        DropdownMenuItem(text = { Text("Rename") }, onClick = {
+            onDismiss()
+            onRename()
+        })
         DropdownMenuItem(
             text = { Text(if (ch.favorite) "Unfavorite" else "Favorite") },
-            onClick = { onDismiss(); onToggleFavorite() },
+            onClick = {
+                onDismiss()
+                onToggleFavorite()
+            },
         )
         DropdownMenuItem(
             text = { Text(if (hasIcon) "Change icon" else "Add icon") },
-            onClick = { onDismiss(); onEditIcon() },
+            onClick = {
+                onDismiss()
+                onEditIcon()
+            },
         )
         if (!ch.isDefault) {
             DropdownMenuItem(
                 text = { Text(if (ch.automation) "Unmark automation" else "Mark as automation") },
-                onClick = { onDismiss(); onToggleAutomation() },
+                onClick = {
+                    onDismiss()
+                    onToggleAutomation()
+                },
             )
-            DropdownMenuItem(text = { Text("Delete") }, onClick = { onDismiss(); onDelete() })
+            DropdownMenuItem(text = { Text("Delete") }, onClick = {
+                onDismiss()
+                onDelete()
+            })
         }
     }
 }
 
 /** Preset avatar colors for the channel-icon color picker. */
-private val AVATAR_COLORS = listOf(
-    "#E57373", "#F06292", "#BA68C8", "#9575CD", "#7986CB",
-    "#64B5F6", "#4FC3F7", "#4DD0E1", "#4DB6AC", "#81C784",
-    "#AED581", "#FFD54F", "#FFB74D", "#FF8A65", "#A1887F",
-    "#90A4AE",
-)
+private val AVATAR_COLORS =
+    listOf(
+        "#E57373",
+        "#F06292",
+        "#BA68C8",
+        "#9575CD",
+        "#7986CB",
+        "#64B5F6",
+        "#4FC3F7",
+        "#4DD0E1",
+        "#4DB6AC",
+        "#81C784",
+        "#AED581",
+        "#FFD54F",
+        "#FFB74D",
+        "#FF8A65",
+        "#A1887F",
+        "#90A4AE",
+    )
 
 /** A small grid of preset color swatches. */
 @Composable
@@ -1334,12 +1469,13 @@ private fun ColorPickerGrid(onPick: (String) -> Unit) {
             Row(modifier = Modifier.padding(vertical = 4.dp)) {
                 AVATAR_COLORS.subList(rowStart, minOf(rowStart + 5, AVATAR_COLORS.size)).forEach { color ->
                     Box(
-                        modifier = Modifier
-                            .size(36.dp)
-                            .padding(3.dp)
-                            .clip(CircleShape)
-                            .background(parseHexColor(color))
-                            .clickable { onPick(color) },
+                        modifier =
+                            Modifier
+                                .size(36.dp)
+                                .padding(3.dp)
+                                .clip(CircleShape)
+                                .background(parseHexColor(color))
+                                .clickable { onPick(color) },
                     )
                 }
             }
@@ -1429,13 +1565,14 @@ private fun ChannelDrawer(
                 val isCurrent = ch.chatId == currentChatId
                 var menuOpen by remember { mutableStateOf(false) }
                 Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .clip(RoundedCornerShape(8.dp))
-                        .background(if (isCurrent) IrisColors.chipSelected else Color.Transparent)
-                        .combinedClickable(onClick = { onOpen(ch) }, onLongClick = { menuOpen = true })
-                        .rightClick { menuOpen = true }
-                        .padding(horizontal = 10.dp, vertical = 6.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .clip(RoundedCornerShape(8.dp))
+                            .background(if (isCurrent) IrisColors.chipSelected else Color.Transparent)
+                            .combinedClickable(onClick = { onOpen(ch) }, onLongClick = { menuOpen = true })
+                            .rightClick { menuOpen = true }
+                            .padding(horizontal = 10.dp, vertical = 6.dp),
                 ) {
                     Row(verticalAlignment = Alignment.CenterVertically) {
                         ChannelAvatar(ch, 28.dp)
@@ -1495,32 +1632,37 @@ private fun ChannelRail(
     onOpenSettings: () -> Unit,
 ) {
     Column(
-        modifier = Modifier
-            .width(280.dp)
-            .fillMaxHeight()
-            .focusRequester(focusRequester)
-            .focusable()
-            .onPreviewKeyEvent { e ->
-                if (e.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
-                when (e.key) {
-                    Key.DirectionUp -> {
-                        if (channels.isNotEmpty()) {
-                            onSelectedIndex((selectedIndex - 1 + channels.size) % channels.size)
+        modifier =
+            Modifier
+                .width(280.dp)
+                .fillMaxHeight()
+                .focusRequester(focusRequester)
+                .focusable()
+                .onPreviewKeyEvent { e ->
+                    if (e.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
+                    when (e.key) {
+                        Key.DirectionUp -> {
+                            if (channels.isNotEmpty()) {
+                                onSelectedIndex((selectedIndex - 1 + channels.size) % channels.size)
+                            }
+                            true
+                        }
+
+                        Key.DirectionDown -> {
+                            if (channels.isNotEmpty()) onSelectedIndex((selectedIndex + 1) % channels.size)
+                            true
+                        }
+
+                        Key.Enter -> {
+                            channels.getOrNull(selectedIndex)?.let { onOpen(it) }
+                            true
+                        }
+
+                        else -> {
+                            false
                         }
-                        true
                     }
-                    Key.DirectionDown -> {
-                        if (channels.isNotEmpty()) onSelectedIndex((selectedIndex + 1) % channels.size)
-                        true
-                    }
-                    Key.Enter -> {
-                        channels.getOrNull(selectedIndex)?.let { onOpen(it) }
-                        true
-                    }
-                    else -> false
-                }
-            }
-            .padding(12.dp),
+                }.padding(12.dp),
     ) {
         Text(
             "Channels",
@@ -1536,28 +1678,29 @@ private fun ChannelRail(
                 val isSelected = ch.chatId == channels.getOrNull(selectedIndex)?.chatId
                 var menuOpen by remember { mutableStateOf(false) }
                 Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .clip(RoundedCornerShape(8.dp))
-                        .background(
-                            when {
-                                isCurrent -> IrisColors.chipSelected
-                                isSelected -> IrisColors.rowSelected
-                                else -> Color.Transparent
-                            },
-                        )
-                        .combinedClickable(onClick = { onOpen(ch) }, onLongClick = { menuOpen = true })
-                        .rightClick { menuOpen = true }
-                        .padding(horizontal = 10.dp, vertical = 6.dp),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .clip(RoundedCornerShape(8.dp))
+                            .background(
+                                when {
+                                    isCurrent -> IrisColors.chipSelected
+                                    isSelected -> IrisColors.rowSelected
+                                    else -> Color.Transparent
+                                },
+                            ).combinedClickable(onClick = { onOpen(ch) }, onLongClick = { menuOpen = true })
+                            .rightClick { menuOpen = true }
+                            .padding(horizontal = 10.dp, vertical = 6.dp),
                 ) {
                     Row(verticalAlignment = Alignment.CenterVertically) {
                         // M7: accent bar marks the active channel.
                         Box(
-                            modifier = Modifier
-                                .width(3.dp)
-                                .height(22.dp)
-                                .clip(RoundedCornerShape(2.dp))
-                                .background(if (isCurrent) IrisColors.primary else Color.Transparent),
+                            modifier =
+                                Modifier
+                                    .width(3.dp)
+                                    .height(22.dp)
+                                    .clip(RoundedCornerShape(2.dp))
+                                    .background(if (isCurrent) IrisColors.primary else Color.Transparent),
                         )
                         Spacer(modifier = Modifier.width(8.dp))
                         ChannelAvatar(ch, 28.dp)
@@ -1604,15 +1747,17 @@ private fun InspectorPane(
     threads: List<ChannelInfo>,
     items: List<ChatItem>,
 ) {
-    val lastAssistant = items.lastOrNull {
-        it is MessageItem && it.role == ROLE_ASSISTANT && !it.streaming
-    } as? MessageItem
+    val lastAssistant =
+        items.lastOrNull {
+            it is MessageItem && it.role == ROLE_ASSISTANT && !it.streaming
+        } as? MessageItem
     Column(
-        modifier = Modifier
-            .width(300.dp)
-            .fillMaxHeight()
-            .verticalScroll(rememberScrollState())
-            .padding(12.dp),
+        modifier =
+            Modifier
+                .width(300.dp)
+                .fillMaxHeight()
+                .verticalScroll(rememberScrollState())
+                .padding(12.dp),
     ) {
         Text(
             "Inspector",
@@ -1637,20 +1782,24 @@ private fun InspectorPane(
 }
 
 @Composable
-private fun InfoRow(label: String, value: String) {
+private fun InfoRow(
+    label: String,
+    value: String,
+) {
     Row(modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp)) {
         Text(label, fontSize = 12.sp, color = IrisColors.textDim, modifier = Modifier.width(70.dp))
         Text(value, fontSize = 12.sp, modifier = Modifier.weight(1f))
     }
 }
 
-private fun statusLabel(state: GatewayClient.State): String = when (state) {
-    GatewayClient.State.Disconnected -> "offline"
-    GatewayClient.State.Connecting -> "connecting…"
-    GatewayClient.State.Reconnecting -> "reconnecting…"
-    is GatewayClient.State.Connected -> "connected"
-    is GatewayClient.State.AuthFailed -> "auth failed"
-}
+private fun statusLabel(state: GatewayClient.State): String =
+    when (state) {
+        GatewayClient.State.Disconnected -> "offline"
+        GatewayClient.State.Connecting -> "connecting…"
+        GatewayClient.State.Reconnecting -> "reconnecting…"
+        is GatewayClient.State.Connected -> "connected"
+        is GatewayClient.State.AuthFailed -> "auth failed"
+    }
 
 /** M6: command palette (Ctrl/Cmd+K) — all actions, filterable. */
 @Composable
@@ -1678,11 +1827,12 @@ private fun CommandPalette(
                 } else {
                     filtered.forEach { (id, label) ->
                         Row(
-                            modifier = Modifier
-                                .fillMaxWidth()
-                                .clip(RoundedCornerShape(6.dp))
-                                .clickable { onAction(id) }
-                                .padding(vertical = 6.dp, horizontal = 4.dp),
+                            modifier =
+                                Modifier
+                                    .fillMaxWidth()
+                                    .clip(RoundedCornerShape(6.dp))
+                                    .clickable { onAction(id) }
+                                    .padding(vertical = 6.dp, horizontal = 4.dp),
                         ) {
                             Text(label, fontSize = 13.sp)
                         }
@@ -1707,10 +1857,11 @@ private fun TopicSwitcher(
     onDeleteThread: (ChannelInfo) -> Unit,
 ) {
     Row(
-        modifier = Modifier
-            .fillMaxWidth()
-            .horizontalScroll(rememberScrollState())
-            .padding(horizontal = 12.dp, vertical = 6.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .horizontalScroll(rememberScrollState())
+                .padding(horizontal = 12.dp, vertical = 6.dp),
         horizontalArrangement = Arrangement.spacedBy(6.dp),
     ) {
         TopicChip("General", currentThreadId == null, onClick = onGeneral)
@@ -1744,21 +1895,21 @@ internal fun TopicChip(
     var menuOpen by remember { mutableStateOf(false) }
     val hasMenu = onRename != null || onDelete != null
     Box(
-        modifier = Modifier
-            .clip(RoundedCornerShape(12.dp))
-            .background(if (selected) IrisColors.primary else IrisColors.chip)
-            .then(
-                if (hasMenu) {
-                    // Tap (both platforms) + long-press (touch / held mouse) +
-                    // right-click (desktop mouse, no-op on touch).
-                    Modifier
-                        .combinedClickable(onClick = onClick, onLongClick = { menuOpen = true })
-                        .rightClick { menuOpen = true }
-                } else {
-                    Modifier.clickable(onClick = onClick)
-                }
-            )
-            .padding(horizontal = 10.dp, vertical = 5.dp),
+        modifier =
+            Modifier
+                .clip(RoundedCornerShape(12.dp))
+                .background(if (selected) IrisColors.primary else IrisColors.chip)
+                .then(
+                    if (hasMenu) {
+                        // Tap (both platforms) + long-press (touch / held mouse) +
+                        // right-click (desktop mouse, no-op on touch).
+                        Modifier
+                            .combinedClickable(onClick = onClick, onLongClick = { menuOpen = true })
+                            .rightClick { menuOpen = true }
+                    } else {
+                        Modifier.clickable(onClick = onClick)
+                    },
+                ).padding(horizontal = 10.dp, vertical = 5.dp),
     ) {
         Text(label, fontSize = 12.sp, color = if (selected) Color.White else IrisColors.textTertiary)
         if (hasMenu) {
@@ -1811,10 +1962,11 @@ private fun SearchOverlay(
 
     Box(modifier = Modifier.fillMaxSize().background(Color.Black.copy(alpha = 0.5f))) {
         Column(
-            modifier = Modifier
-                .fillMaxSize()
-                .background(MaterialTheme.colorScheme.surface)
-                .padding(16.dp),
+            modifier =
+                Modifier
+                    .fillMaxSize()
+                    .background(MaterialTheme.colorScheme.surface)
+                    .padding(16.dp),
         ) {
             Row(verticalAlignment = Alignment.CenterVertically) {
                 Text("Search", style = MaterialTheme.typography.titleMedium, modifier = Modifier.weight(1f))
@@ -1864,16 +2016,21 @@ private fun SearchOverlay(
 }
 
 @Composable
-private fun SearchHitRow(hit: SearchHit, channels: ChannelStore, onClick: () -> Unit) {
+private fun SearchHitRow(
+    hit: SearchHit,
+    channels: ChannelStore,
+    onClick: () -> Unit,
+) {
     val channel = channels.byId(hit.chatId)
     val thread = hit.threadId?.let { channels.byId(it) }
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(10.dp))
-            .background(IrisColors.panel)
-            .clickable(onClick = onClick)
-            .padding(10.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(10.dp))
+                .background(IrisColors.panel)
+                .clickable(onClick = onClick)
+                .padding(10.dp),
     ) {
         Row(verticalAlignment = Alignment.CenterVertically) {
             Text(
@@ -1920,25 +2077,34 @@ private fun NameDialog(
 }
 
 /** Human-readable connection status for the status-bubble tap toast. */
-private fun statusToastText(state: GatewayClient.State): String = when (state) {
-    is GatewayClient.State.Connected -> "Connected to Hermes"
-    GatewayClient.State.Connecting -> "Connecting to Hermes"
-    GatewayClient.State.Reconnecting -> "Re-Connecting to Hermes"
-    GatewayClient.State.Disconnected -> "Unpaired from Hermes"
-    is GatewayClient.State.AuthFailed -> "Unpaired from Hermes"
-}
+private fun statusToastText(state: GatewayClient.State): String =
+    when (state) {
+        is GatewayClient.State.Connected -> "Connected to Hermes"
+        GatewayClient.State.Connecting -> "Connecting to Hermes"
+        GatewayClient.State.Reconnecting -> "Re-Connecting to Hermes"
+        GatewayClient.State.Disconnected -> "Unpaired from Hermes"
+        is GatewayClient.State.AuthFailed -> "Unpaired from Hermes"
+    }
 
 /** Header status bubble: green = connected, yellow pulsing = (re)connecting,
  *  red = not paired / offline. Tapping shows a toast with the status text. */
 @Composable
-private fun StatusBubble(state: GatewayClient.State, onClick: () -> Unit) {
-    val (color, pulsing) = when (state) {
-        is GatewayClient.State.Connected -> IrisColors.statusGreen to false
-        GatewayClient.State.Connecting,
-        GatewayClient.State.Reconnecting -> IrisColors.statusAmber to true
-        GatewayClient.State.Disconnected,
-        is GatewayClient.State.AuthFailed -> IrisColors.statusRed to false
-    }
+private fun StatusBubble(
+    state: GatewayClient.State,
+    onClick: () -> Unit,
+) {
+    val (color, pulsing) =
+        when (state) {
+            is GatewayClient.State.Connected -> IrisColors.statusGreen to false
+
+            GatewayClient.State.Connecting,
+            GatewayClient.State.Reconnecting,
+            -> IrisColors.statusAmber to true
+
+            GatewayClient.State.Disconnected,
+            is GatewayClient.State.AuthFailed,
+            -> IrisColors.statusRed to false
+        }
     val alpha = remember { Animatable(1f) }
     LaunchedEffect(pulsing) {
         if (pulsing) {
@@ -1952,17 +2118,19 @@ private fun StatusBubble(state: GatewayClient.State, onClick: () -> Unit) {
     }
     // 10dp visual dot with a larger (24dp) transparent tap target.
     Box(
-        modifier = Modifier
-            .padding(7.dp)
-            .clip(CircleShape)
-            .clickable(onClick = onClick),
+        modifier =
+            Modifier
+                .padding(7.dp)
+                .clip(CircleShape)
+                .clickable(onClick = onClick),
         contentAlignment = Alignment.Center,
     ) {
         Box(
-            modifier = Modifier
-                .size(10.dp)
-                .clip(CircleShape)
-                .background(color.copy(alpha = alpha.value)),
+            modifier =
+                Modifier
+                    .size(10.dp)
+                    .clip(CircleShape)
+                    .background(color.copy(alpha = alpha.value)),
         )
     }
 }
@@ -1978,17 +2146,19 @@ private fun ToastOverlay(message: String?) {
     Box(modifier = Modifier.fillMaxSize()) {
         AnimatedVisibility(
             visible = message != null,
-            modifier = Modifier
-                .align(Alignment.BottomCenter)
-                .padding(bottom = 24.dp),
+            modifier =
+                Modifier
+                    .align(Alignment.BottomCenter)
+                    .padding(bottom = 24.dp),
             enter = fadeIn(tween(150)),
             exit = fadeOut(tween(300)),
         ) {
             Box(
-                modifier = Modifier
-                    .clip(RoundedCornerShape(20.dp))
-                    .background(Color.Black.copy(alpha = 0.82f))
-                    .padding(horizontal = 16.dp, vertical = 10.dp),
+                modifier =
+                    Modifier
+                        .clip(RoundedCornerShape(20.dp))
+                        .background(Color.Black.copy(alpha = 0.82f))
+                        .padding(horizontal = 16.dp, vertical = 10.dp),
             ) {
                 Text(shown, color = Color.White, fontSize = 13.sp)
             }
@@ -2003,19 +2173,21 @@ private fun NotificationBanner(
     onOpen: () -> Unit,
     onDismiss: () -> Unit,
 ) {
-    val accent = when (banner.kind) {
-        "approval" -> IrisColors.statusAmber
-        "clarify" -> IrisColors.primary
-        "cron" -> IrisColors.statusGreen
-        else -> IrisColors.textDim
-    }
+    val accent =
+        when (banner.kind) {
+            "approval" -> IrisColors.statusAmber
+            "clarify" -> IrisColors.primary
+            "cron" -> IrisColors.statusGreen
+            else -> IrisColors.textDim
+        }
     Row(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(12.dp))
-            .background(accent.copy(alpha = 0.12f))
-            .clickable(onClick = onOpen)
-            .padding(horizontal = 12.dp, vertical = 8.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(12.dp))
+                .background(accent.copy(alpha = 0.12f))
+                .clickable(onClick = onOpen)
+                .padding(horizontal = 12.dp, vertical = 8.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
         Column(modifier = Modifier.weight(1f)) {
@@ -2043,16 +2215,18 @@ private fun MessageBubble(
     val isUser = msg.role == ROLE_USER
     val isCommentary = msg.isCommentary
     val userTheme = LocalUserTheme.current
-    val bubbleColor = when {
-        isUser -> userTheme.userBubble
-        isCommentary -> IrisColors.bubbleCommentary
-        else -> userTheme.agentBubble
-    }
-    val textColor = when {
-        isUser -> userTheme.userBubble.contrastText()
-        isCommentary -> IrisColors.onSurface.copy(alpha = 0.55f)
-        else -> userTheme.agentBubble.contrastText()
-    }
+    val bubbleColor =
+        when {
+            isUser -> userTheme.userBubble
+            isCommentary -> IrisColors.bubbleCommentary
+            else -> userTheme.agentBubble
+        }
+    val textColor =
+        when {
+            isUser -> userTheme.userBubble.contrastText()
+            isCommentary -> IrisColors.onSurface.copy(alpha = 0.55f)
+            else -> userTheme.agentBubble.contrastText()
+        }
     val time = formatTime(msg.ts)
     Row(
         modifier = Modifier.fillMaxWidth(),
@@ -2065,26 +2239,28 @@ private fun MessageBubble(
             Spacer(modifier = Modifier.width(6.dp))
         }
         Column(
-            modifier = Modifier
-                .widthIn(max = maxWidth)
-                .clip(RoundedCornerShape(14.dp))
-                .background(if (selected) IrisColors.chipSelected else bubbleColor)
-                .then(
-                    // Long-press / right-click enters (or toggles within) message
-                    // selection; a plain tap toggles while selecting, or retries a
-                    // failed user send otherwise. Attached always so the long-press
-                    // affordance exists even outside selection mode.
-                    Modifier
-                        .combinedClickable(
-                            onClick = {
-                                if (selectionMode) onToggleSelect()
-                                else if (isUser && msg.status == MsgStatus.Failed) onRetry()
-                            },
-                            onLongClick = { onLongPress() },
-                        )
-                        .rightClick { onLongPress() }
-                )
-                .padding(horizontal = 12.dp, vertical = 8.dp),
+            modifier =
+                Modifier
+                    .widthIn(max = maxWidth)
+                    .clip(RoundedCornerShape(14.dp))
+                    .background(if (selected) IrisColors.chipSelected else bubbleColor)
+                    .then(
+                        // Long-press / right-click enters (or toggles within) message
+                        // selection; a plain tap toggles while selecting, or retries a
+                        // failed user send otherwise. Attached always so the long-press
+                        // affordance exists even outside selection mode.
+                        Modifier
+                            .combinedClickable(
+                                onClick = {
+                                    if (selectionMode) {
+                                        onToggleSelect()
+                                    } else if (isUser && msg.status == MsgStatus.Failed) {
+                                        onRetry()
+                                    }
+                                },
+                                onLongClick = { onLongPress() },
+                            ).rightClick { onLongPress() },
+                    ).padding(horizontal = 12.dp, vertical = 8.dp),
         ) {
             // Reasoning block above the answer (assistant, non-commentary).
             if (!isUser && !isCommentary && !msg.reasoning.isNullOrBlank()) {
@@ -2097,8 +2273,9 @@ private fun MessageBubble(
                 // in replies.
                 if (msg.text.isNotBlank() || msg.streaming) {
                     MarkdownText(
-                        text = msg.text.prepareForMarkdown().preserveNewlinesAsHardBreaks() +
-                            if (msg.streaming) " ▉" else "",
+                        text =
+                            msg.text.prepareForMarkdown().preserveNewlinesAsHardBreaks() +
+                                if (msg.streaming) " ▉" else "",
                         color = textColor,
                         fontSize = 15.sp,
                         isStreaming = msg.streaming,
@@ -2115,13 +2292,21 @@ private fun MessageBubble(
                         Text(time, fontSize = 10.sp, color = textColor.copy(alpha = 0.6f))
                     }
                     when (msg.status) {
-                        MsgStatus.Pending ->
+                        MsgStatus.Pending -> {
                             Text(" sending…", fontSize = 10.sp, color = textColor.copy(alpha = 0.6f))
-                        MsgStatus.Sent ->
+                        }
+
+                        MsgStatus.Sent -> {
                             Text(" ✓", fontSize = 10.sp, color = textColor.copy(alpha = 0.8f))
-                        MsgStatus.Read ->
+                        }
+
+                        MsgStatus.Read -> {
                             Text(" ✓✓", fontSize = 10.sp, color = textColor.copy(alpha = 0.8f))
-                        MsgStatus.Failed -> Unit
+                        }
+
+                        MsgStatus.Failed -> {
+                            Unit
+                        }
                     }
                 }
                 if (msg.status == MsgStatus.Failed) {
@@ -2140,8 +2325,9 @@ private fun MessageBubble(
                     // bubble; single newlines become hard breaks (models write
                     // status lines and wrapped text expecting a break per line,
                     // same as user input); the ▉ cursor is kept while streaming.
-                    val displayText = msg.text.prepareForMarkdown().preserveNewlinesAsHardBreaks() +
-                        if (msg.streaming) " ▉" else ""
+                    val displayText =
+                        msg.text.prepareForMarkdown().preserveNewlinesAsHardBreaks() +
+                            if (msg.streaming) " ▉" else ""
                     MarkdownText(
                         text = displayText,
                         color = textColor,
@@ -2168,7 +2354,7 @@ private fun MessageBubble(
                         buildString {
                             msg.model?.let { append(it) }
                             if (msg.model != null && msg.tokens != null) append(" · ")
-                            msg.tokens?.let { append("${it} tok") }
+                            msg.tokens?.let { append("$it tok") }
                         },
                         color = textColor.copy(alpha = 0.4f),
                         fontSize = 10.sp,
@@ -2196,15 +2382,16 @@ private fun MessageBubble(
 @Composable
 private fun SelectionCheck(selected: Boolean) {
     Box(
-        modifier = Modifier
-            .size(22.dp)
-            .clip(CircleShape)
-            .background(if (selected) IrisColors.primary else Color.Transparent)
-            .border(
-                width = if (selected) 0.dp else 1.5.dp,
-                color = IrisColors.textDim,
-                shape = CircleShape,
-            ),
+        modifier =
+            Modifier
+                .size(22.dp)
+                .clip(CircleShape)
+                .background(if (selected) IrisColors.primary else Color.Transparent)
+                .border(
+                    width = if (selected) 0.dp else 1.5.dp,
+                    color = IrisColors.textDim,
+                    shape = CircleShape,
+                ),
         contentAlignment = Alignment.Center,
     ) {
         if (selected) Text("✓", color = Color.White, fontSize = 12.sp)
@@ -2213,14 +2400,19 @@ private fun SelectionCheck(selected: Boolean) {
 
 /** Toolbar shown in place of the composer while messages are selected. */
 @Composable
-private fun SelectionToolbar(count: Int, onCancel: () -> Unit, onDelete: () -> Unit) {
+private fun SelectionToolbar(
+    count: Int,
+    onCancel: () -> Unit,
+    onDelete: () -> Unit,
+) {
     Row(
-        modifier = Modifier
-            .fillMaxWidth()
-            .padding(horizontal = 12.dp, vertical = 8.dp)
-            .clip(RoundedCornerShape(28.dp))
-            .background(IrisColors.surface)
-            .padding(horizontal = 8.dp, vertical = 4.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 12.dp, vertical = 8.dp)
+                .clip(RoundedCornerShape(28.dp))
+                .background(IrisColors.surface)
+                .padding(horizontal = 8.dp, vertical = 4.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
         HeaderIconButton(onClick = onCancel) {
@@ -2233,11 +2425,12 @@ private fun SelectionToolbar(count: Int, onCancel: () -> Unit, onDelete: () -> U
             modifier = Modifier.weight(1f),
         )
         Box(
-            modifier = Modifier
-                .clip(RoundedCornerShape(20.dp))
-                .background(if (count > 0) IrisColors.primary else IrisColors.primary.copy(alpha = 0.35f))
-                .clickable(enabled = count > 0) { onDelete() }
-                .padding(horizontal = 16.dp, vertical = 8.dp),
+            modifier =
+                Modifier
+                    .clip(RoundedCornerShape(20.dp))
+                    .background(if (count > 0) IrisColors.primary else IrisColors.primary.copy(alpha = 0.35f))
+                    .clickable(enabled = count > 0) { onDelete() }
+                    .padding(horizontal = 16.dp, vertical = 8.dp),
             contentAlignment = Alignment.Center,
         ) {
             Text("🗑 Delete", color = Color.White, fontSize = 14.sp)
@@ -2276,14 +2469,18 @@ private fun MediaImage(media: MediaItem) {
 
     if (loading || bitmap == null) {
         Box(
-            modifier = Modifier
-                .size(120.dp)
-                .clip(RoundedCornerShape(10.dp))
-                .background(IrisColors.panel),
+            modifier =
+                Modifier
+                    .size(120.dp)
+                    .clip(RoundedCornerShape(10.dp))
+                    .background(IrisColors.panel),
             contentAlignment = Alignment.Center,
         ) {
-            if (media.localPath == null) Text("downloading…", fontSize = 11.sp)
-            else CircularProgressIndicator(modifier = Modifier.size(20.dp), strokeWidth = 2.dp)
+            if (media.localPath == null) {
+                Text("downloading…", fontSize = 11.sp)
+            } else {
+                CircularProgressIndicator(modifier = Modifier.size(20.dp), strokeWidth = 2.dp)
+            }
         }
         return
     }
@@ -2292,33 +2489,40 @@ private fun MediaImage(media: MediaItem) {
     // Preserve the image's aspect ratio, capping the dominant dimension at
     // 260.dp so a chat image never dominates the screen (the other dimension
     // follows the ratio).
-    val (imgW, imgH) = if (aspect >= 1f) 260.dp to (260 / aspect).dp
-    else (260 * aspect).dp to 260.dp
+    val (imgW, imgH) =
+        if (aspect >= 1f) {
+            260.dp to (260 / aspect).dp
+        } else {
+            (260 * aspect).dp to 260.dp
+        }
     Image(
         bitmap = bmp,
         contentDescription = media.filename,
         contentScale = ContentScale.FillBounds,
-        modifier = Modifier
-            .width(imgW)
-            .height(imgH)
-            .clip(RoundedCornerShape(10.dp))
-            .clickable { showFull = true },
+        modifier =
+            Modifier
+                .width(imgW)
+                .height(imgH)
+                .clip(RoundedCornerShape(10.dp))
+                .clickable { showFull = true },
     )
     if (showFull) {
         Box(
-            modifier = Modifier
-                .fillMaxSize()
-                .background(Color.Black)
-                .clickable { showFull = false },
+            modifier =
+                Modifier
+                    .fillMaxSize()
+                    .background(Color.Black)
+                    .clickable { showFull = false },
             contentAlignment = Alignment.Center,
         ) {
             Image(
                 bitmap = bitmap!!,
                 contentDescription = media.filename,
                 contentScale = ContentScale.Fit,
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .fillMaxHeight(0.9f),
+                modifier =
+                    Modifier
+                        .fillMaxWidth()
+                        .fillMaxHeight(0.9f),
             )
         }
     }
@@ -2327,13 +2531,13 @@ private fun MediaImage(media: MediaItem) {
 @Composable
 private fun MediaDocChip(media: MediaItem) {
     Row(
-        modifier = Modifier
-            .clip(RoundedCornerShape(10.dp))
-            .background(IrisColors.panel)
-            .clickable {
-                media.localPath?.let { openDocument(it, media.mime) }
-            }
-            .padding(horizontal = 10.dp, vertical = 8.dp),
+        modifier =
+            Modifier
+                .clip(RoundedCornerShape(10.dp))
+                .background(IrisColors.panel)
+                .clickable {
+                    media.localPath?.let { openDocument(it, media.mime) }
+                }.padding(horizontal = 10.dp, vertical = 8.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
         Text("📄", fontSize = 16.sp)
@@ -2345,25 +2549,31 @@ private fun MediaDocChip(media: MediaItem) {
     }
 }
 
-private fun fmtSize(bytes: Long): String = when {
-    bytes >= 1_048_576 -> "%.1f MB".format(bytes / 1_048_576.0)
-    bytes >= 1024 -> "%.0f KB".format(bytes / 1024.0)
-    else -> "$bytes B"
-}
+private fun fmtSize(bytes: Long): String =
+    when {
+        bytes >= 1_048_576 -> "%.1f MB".format(bytes / 1_048_576.0)
+        bytes >= 1024 -> "%.0f KB".format(bytes / 1024.0)
+        else -> "$bytes B"
+    }
 
 /** M4: composer attachment chip (uploading / ready / error). */
 @Composable
-private fun AttachmentChip(att: IrisController.PendingAttachment, onRemove: () -> Unit) {
-    val (icon, label) = when {
-        att.error != null -> "⚠️" to "${att.filename} — ${att.error}"
-        att.uploading -> "⏳" to "${att.filename} (${fmtSize(att.size)})"
-        else -> "📎" to "${att.filename} (${fmtSize(att.size)})"
-    }
+private fun AttachmentChip(
+    att: IrisController.PendingAttachment,
+    onRemove: () -> Unit,
+) {
+    val (icon, label) =
+        when {
+            att.error != null -> "⚠️" to "${att.filename} — ${att.error}"
+            att.uploading -> "⏳" to "${att.filename} (${fmtSize(att.size)})"
+            else -> "📎" to "${att.filename} (${fmtSize(att.size)})"
+        }
     Row(
-        modifier = Modifier
-            .clip(RoundedCornerShape(12.dp))
-            .background(IrisColors.chip)
-            .padding(horizontal = 8.dp, vertical = 5.dp),
+        modifier =
+            Modifier
+                .clip(RoundedCornerShape(12.dp))
+                .background(IrisColors.chip)
+                .padding(horizontal = 8.dp, vertical = 5.dp),
         verticalAlignment = Alignment.CenterVertically,
     ) {
         Text(icon, fontSize = 12.sp)
@@ -2381,7 +2591,11 @@ private fun AttachmentChip(att: IrisController.PendingAttachment, onRemove: () -
  * expanded. Tap to toggle.
  */
 @Composable
-private fun ReasoningBlock(reasoning: String, autoCollapse: Boolean, bubbleColor: Color) {
+private fun ReasoningBlock(
+    reasoning: String,
+    autoCollapse: Boolean,
+    bubbleColor: Color,
+) {
     val clipboard = LocalClipboardManager.current
     var expanded by remember(autoCollapse) {
         mutableStateOf(!autoCollapse || reasoning.length <= 240)
@@ -2391,18 +2605,20 @@ private fun ReasoningBlock(reasoning: String, autoCollapse: Boolean, bubbleColor
     // color is, so the reasoning block always matches the bubble while staying
     // visually distinct from the message content. Text is derived from the
     // effective (darkened) background so it stays readable on any bubble color.
-    val effective = Color(
-        red = bubbleColor.red * 0.4f,
-        green = bubbleColor.green * 0.4f,
-        blue = bubbleColor.blue * 0.4f,
-    )
+    val effective =
+        Color(
+            red = bubbleColor.red * 0.4f,
+            green = bubbleColor.green * 0.4f,
+            blue = bubbleColor.blue * 0.4f,
+        )
     val textColor = effective.contrastText()
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(8.dp))
-            .background(Color.Black.copy(alpha = 0.6f))
-            .padding(8.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(8.dp))
+                .background(Color.Black.copy(alpha = 0.6f))
+                .padding(8.dp),
     ) {
         Row(verticalAlignment = Alignment.CenterVertically) {
             Text(
@@ -2410,9 +2626,10 @@ private fun ReasoningBlock(reasoning: String, autoCollapse: Boolean, bubbleColor
                 fontSize = 12.sp,
                 fontWeight = FontWeight.SemiBold,
                 color = textColor,
-                modifier = Modifier
-                    .weight(1f)
-                    .clickable { expanded = !expanded },
+                modifier =
+                    Modifier
+                        .weight(1f)
+                        .clickable { expanded = !expanded },
             )
             TextButton(onClick = {
                 clipboard.setText(AnnotatedString(reasoning))
@@ -2443,26 +2660,32 @@ private fun ReasoningBlock(reasoning: String, autoCollapse: Boolean, bubbleColor
  * ✓/✗ + duration on completion. Verbosity controlled by [detail].
  */
 @Composable
-private fun ToolCard(tool: ToolItem, detail: ToolDetail) {
+private fun ToolCard(
+    tool: ToolItem,
+    detail: ToolDetail,
+) {
     // Everything starts expanded (show the full call + output); Truncated
     // starts collapsed and reveals them on tap.
     var expanded by remember(detail) { mutableStateOf(detail == ToolDetail.EVERYTHING) }
-    val status = when {
-        !tool.done -> null
-        tool.ok -> "✓"
-        else -> "✗"
-    }
-    val statusColor = when {
-        tool.ok -> IrisColors.statusGreen
-        else -> IrisColors.statusRed
-    }
+    val status =
+        when {
+            !tool.done -> null
+            tool.ok -> "✓"
+            else -> "✗"
+        }
+    val statusColor =
+        when {
+            tool.ok -> IrisColors.statusGreen
+            else -> IrisColors.statusRed
+        }
     val preview = tool.preview ?: tool.note
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(10.dp))
-            .background(IrisColors.panel)
-            .padding(horizontal = 10.dp, vertical = 8.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(10.dp))
+                .background(IrisColors.panel)
+                .padding(horizontal = 10.dp, vertical = 8.dp),
     ) {
         Row(verticalAlignment = Alignment.CenterVertically) {
             if (!tool.done) {
@@ -2480,9 +2703,10 @@ private fun ToolCard(tool: ToolItem, detail: ToolDetail) {
                 fontSize = 13.sp,
                 fontWeight = FontWeight.Medium,
                 color = IrisColors.textBright,
-                modifier = Modifier
-                    .weight(1f)
-                    .clickable { expanded = !expanded },
+                modifier =
+                    Modifier
+                        .weight(1f)
+                        .clickable { expanded = !expanded },
             )
             if (tool.duration != null) {
                 Text(
@@ -2526,11 +2750,12 @@ private fun ToolCard(tool: ToolItem, detail: ToolDetail) {
 }
 
 internal val ToolDetail.label: String
-    get() = when (this) {
-        ToolDetail.EVERYTHING -> "everything"
-        ToolDetail.TRUNCATED -> "truncated"
-        ToolDetail.NOTHING -> "nothing"
-    }
+    get() =
+        when (this) {
+            ToolDetail.EVERYTHING -> "everything"
+            ToolDetail.TRUNCATED -> "truncated"
+            ToolDetail.NOTHING -> "nothing"
+        }
 
 // ── Slash-command drawer ──────────────────────────────────────────────────
 
@@ -2539,11 +2764,14 @@ private const val SLASH_DRAWER_MAX = 8
 
 /** Best fuzzy rank of [query] against a command's name or any of its
  *  aliases; -1 when nothing matches. */
-private fun bestSlashScore(query: String, cmd: SlashCommand): Int {
+private fun bestSlashScore(
+    query: String,
+    cmd: SlashCommand,
+): Int {
     var best = fuzzyScore(query, cmd.name.removePrefix("/"))
     for (alias in cmd.aliases) {
         val s = fuzzyScore(query, alias.removePrefix("/"))
         if (s >= 0 && (best < 0 || s < best)) best = s
     }
     return best
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/commonMain/kotlin/iris/ui/screens/SettingsScreen.kt b/app/shared/src/commonMain/kotlin/iris/ui/screens/SettingsScreen.kt
index 8547169..1eacc9f 100644
--- a/app/shared/src/commonMain/kotlin/iris/ui/screens/SettingsScreen.kt
+++ b/app/shared/src/commonMain/kotlin/iris/ui/screens/SettingsScreen.kt
@@ -8,6 +8,7 @@ import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.FlowRow
 import androidx.compose.foundation.layout.Row
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxSize
@@ -44,9 +45,12 @@ import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import iris.platform.ImageFilePicker
+import iris.platform.decodeImageBytes
 import iris.platform.loadScaledImage
+import iris.platform.readBackdropBytes
 import iris.state.IrisController
 import iris.state.ToolDetail
+import iris.ui.theme.Backdrop
 import iris.ui.theme.BackgroundMode
 import iris.ui.theme.IrisColors
 import iris.ui.theme.LocalUserTheme
@@ -56,11 +60,15 @@ import kotlin.math.roundToInt
  * Settings screen (post-M7): app-level preferences, opened from the channel
  * drawer / rail. More settings land here over time.
  */
+
 /** Which color the picker dialog is editing. */
 private enum class PickerTarget { UserBubble, AgentBubble, Background }
 
 @Composable
-fun SettingsScreen(controller: IrisController, onBack: () -> Unit) {
+fun SettingsScreen(
+    controller: IrisController,
+    onBack: () -> Unit,
+) {
     val threadsEnabled by controller.threadsEnabled.collectAsState()
     val streamingEnabled by controller.streamingEnabled.collectAsState()
     val reasoningAutoCollapse by controller.reasoningAutoCollapse.collectAsState()
@@ -71,10 +79,11 @@ fun SettingsScreen(controller: IrisController, onBack: () -> Unit) {
 
     Box(modifier = Modifier.fillMaxSize().background(theme.background)) {
         Column(
-            modifier = Modifier
-                .fillMaxSize()
-                .verticalScroll(rememberScrollState())
-                .padding(12.dp),
+            modifier =
+                Modifier
+                    .fillMaxSize()
+                    .verticalScroll(rememberScrollState())
+                    .padding(12.dp),
             verticalArrangement = Arrangement.spacedBy(8.dp),
         ) {
             Row(
@@ -220,14 +229,36 @@ fun SettingsScreen(controller: IrisController, onBack: () -> Unit) {
                         ColorSwatch(theme.background) { pickerTarget = PickerTarget.Background }
                     }
                 } else {
+                    Spacer(modifier = Modifier.height(8.dp))
+                    Text("Backdrops", fontSize = 12.sp, color = IrisColors.textDim)
+                    Spacer(modifier = Modifier.height(6.dp))
+                    FlowRow(
+                        horizontalArrangement = Arrangement.spacedBy(8.dp),
+                        verticalArrangement = Arrangement.spacedBy(8.dp),
+                    ) {
+                        Backdrop.ALL.forEach { backdrop ->
+                            BackdropThumb(
+                                backdrop = backdrop,
+                                selected = theme.backgroundImagePath == backdrop.path,
+                                onClick = {
+                                    controller.setBackgroundMode(BackgroundMode.Image)
+                                    controller.setBackgroundImagePath(backdrop.path)
+                                },
+                            )
+                        }
+                    }
                     Spacer(modifier = Modifier.height(8.dp))
                     Row(verticalAlignment = Alignment.CenterVertically) {
                         BackgroundPreview(theme.backgroundImagePath)
                         Spacer(modifier = Modifier.width(8.dp))
                         Column(modifier = Modifier.weight(1f)) {
                             Text(
-                                if (theme.backgroundImagePath.isNullOrBlank()) "No image selected"
-                                else fileNameOf(theme.backgroundImagePath!!),
+                                if (theme.backgroundImagePath.isNullOrBlank()) {
+                                    "No image selected"
+                                } else {
+                                    Backdrop.fromPath(theme.backgroundImagePath)?.name
+                                        ?: fileNameOf(theme.backgroundImagePath!!)
+                                },
                                 fontSize = 12.sp,
                                 color = IrisColors.textDim,
                             )
@@ -328,58 +359,73 @@ fun SettingsScreen(controller: IrisController, onBack: () -> Unit) {
         }
 
         when (pickerTarget) {
-            PickerTarget.UserBubble -> ColorPickerDialog(
-                title = "Your bubble",
-                initialArgb = theme.userBubbleColor,
-                onApply = { controller.setUserBubbleColor(it) },
-                onConfirm = {
-                    controller.setUserBubbleColor(it)
-                    pickerTarget = null
-                },
-                onDismiss = { pickerTarget = null },
-            )
-            PickerTarget.AgentBubble -> ColorPickerDialog(
-                title = "Agent bubble",
-                initialArgb = theme.agentBubbleColor,
-                onApply = { controller.setAgentBubbleColor(it) },
-                onConfirm = {
-                    controller.setAgentBubbleColor(it)
-                    pickerTarget = null
-                },
-                onDismiss = { pickerTarget = null },
-            )
-            PickerTarget.Background -> ColorPickerDialog(
-                title = "Background",
-                initialArgb = theme.backgroundColor,
-                onApply = { controller.setBackgroundColor(it) },
-                onConfirm = {
-                    controller.setBackgroundColor(it)
-                    pickerTarget = null
-                },
-                onDismiss = { pickerTarget = null },
-            )
-            null -> Unit
+            PickerTarget.UserBubble -> {
+                ColorPickerDialog(
+                    title = "Your bubble",
+                    initialArgb = theme.userBubbleColor,
+                    onApply = { controller.setUserBubbleColor(it) },
+                    onConfirm = {
+                        controller.setUserBubbleColor(it)
+                        pickerTarget = null
+                    },
+                    onDismiss = { pickerTarget = null },
+                )
+            }
+
+            PickerTarget.AgentBubble -> {
+                ColorPickerDialog(
+                    title = "Agent bubble",
+                    initialArgb = theme.agentBubbleColor,
+                    onApply = { controller.setAgentBubbleColor(it) },
+                    onConfirm = {
+                        controller.setAgentBubbleColor(it)
+                        pickerTarget = null
+                    },
+                    onDismiss = { pickerTarget = null },
+                )
+            }
+
+            PickerTarget.Background -> {
+                ColorPickerDialog(
+                    title = "Background",
+                    initialArgb = theme.backgroundColor,
+                    onApply = { controller.setBackgroundColor(it) },
+                    onConfirm = {
+                        controller.setBackgroundColor(it)
+                        pickerTarget = null
+                    },
+                    onDismiss = { pickerTarget = null },
+                )
+            }
+
+            null -> {
+                Unit
+            }
         }
     }
 }
 
 /** Material-style back arrow (vector, matches the app's icon weight). */
 @Composable
-private fun BackArrow(size: Dp = 22.dp, color: Color = IrisColors.onSurface) {
+private fun BackArrow(
+    size: Dp = 22.dp,
+    color: Color = IrisColors.onSurface,
+) {
     Canvas(modifier = Modifier.size(size)) {
         val s = this.size.width / 24f
-        val path = Path().apply {
-            moveTo(20f * s, 11f * s)
-            lineTo(7.83f * s, 11f * s)
-            lineTo(13.42f * s, 5.41f * s)
-            lineTo(12f * s, 4f * s)
-            lineTo(4f * s, 12f * s)
-            lineTo(12f * s, 20f * s)
-            lineTo(13.41f * s, 18.59f * s)
-            lineTo(7.83f * s, 13f * s)
-            lineTo(20f * s, 13f * s)
-            close()
-        }
+        val path =
+            Path().apply {
+                moveTo(20f * s, 11f * s)
+                lineTo(7.83f * s, 11f * s)
+                lineTo(13.42f * s, 5.41f * s)
+                lineTo(12f * s, 4f * s)
+                lineTo(4f * s, 12f * s)
+                lineTo(12f * s, 20f * s)
+                lineTo(13.41f * s, 18.59f * s)
+                lineTo(7.83f * s, 13f * s)
+                lineTo(20f * s, 13f * s)
+                close()
+            }
         drawPath(path, color)
     }
 }
@@ -388,11 +434,12 @@ private fun BackArrow(size: Dp = 22.dp, color: Color = IrisColors.onSurface) {
 @Composable
 private fun SettingsCard(content: @Composable () -> Unit) {
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(12.dp))
-            .background(IrisColors.panel)
-            .padding(12.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(12.dp))
+                .background(IrisColors.panel)
+                .padding(12.dp),
     ) {
         content()
     }
@@ -400,14 +447,18 @@ private fun SettingsCard(content: @Composable () -> Unit) {
 
 /** Clickable rounded chip showing a color; opens the picker on tap. */
 @Composable
-private fun ColorSwatch(color: Color, onClick: () -> Unit) {
+private fun ColorSwatch(
+    color: Color,
+    onClick: () -> Unit,
+) {
     Box(
-        modifier = Modifier
-            .size(32.dp)
-            .clip(RoundedCornerShape(8.dp))
-            .background(color)
-            .border(1.dp, IrisColors.divider, RoundedCornerShape(8.dp))
-            .clickable(onClick = onClick),
+        modifier =
+            Modifier
+                .size(32.dp)
+                .clip(RoundedCornerShape(8.dp))
+                .background(color)
+                .border(1.dp, IrisColors.divider, RoundedCornerShape(8.dp))
+                .clickable(onClick = onClick),
     )
 }
 
@@ -416,14 +467,25 @@ private fun ColorSwatch(color: Color, onClick: () -> Unit) {
 private fun BackgroundPreview(path: String?) {
     var bmp by remember(path) { mutableStateOf<ImageBitmap?>(null) }
     LaunchedEffect(path) {
-        bmp = if (path.isNullOrBlank()) null else loadScaledImage(path, 128)
+        bmp =
+            if (path.isNullOrBlank()) {
+                null
+            } else {
+                val bytes = Backdrop.fromPath(path)?.let { readBackdropBytes(it.id) }
+                if (bytes != null) {
+                    decodeImageBytes(bytes, 128)
+                } else {
+                    loadScaledImage(path, 128)
+                }
+            }
     }
     Box(
-        modifier = Modifier
-            .size(44.dp)
-            .clip(RoundedCornerShape(8.dp))
-            .background(IrisColors.panel)
-            .border(1.dp, IrisColors.divider, RoundedCornerShape(8.dp)),
+        modifier =
+            Modifier
+                .size(44.dp)
+                .clip(RoundedCornerShape(8.dp))
+                .background(IrisColors.panel)
+                .border(1.dp, IrisColors.divider, RoundedCornerShape(8.dp)),
         contentAlignment = Alignment.Center,
     ) {
         val b = bmp
@@ -438,6 +500,43 @@ private fun BackgroundPreview(path: String?) {
     }
 }
 
+/** Thumbnail of a bundled backdrop; highlighted when selected. */
+@Composable
+private fun BackdropThumb(
+    backdrop: Backdrop,
+    selected: Boolean,
+    onClick: () -> Unit,
+) {
+    var bmp by remember(backdrop.id) { mutableStateOf<ImageBitmap?>(null) }
+    LaunchedEffect(backdrop.id) {
+        val bytes = readBackdropBytes(backdrop.id)
+        bmp = if (bytes != null) decodeImageBytes(bytes, 128) else null
+    }
+    Box(
+        modifier =
+            Modifier
+                .size(64.dp)
+                .clip(RoundedCornerShape(8.dp))
+                .background(IrisColors.panel)
+                .border(
+                    if (selected) 2.dp else 1.dp,
+                    if (selected) IrisColors.primary else IrisColors.divider,
+                    RoundedCornerShape(8.dp),
+                ).clickable(onClick = onClick),
+        contentAlignment = Alignment.Center,
+    ) {
+        val b = bmp
+        if (b != null) {
+            Image(
+                bitmap = b,
+                contentDescription = backdrop.name,
+                contentScale = ContentScale.Crop,
+                modifier = Modifier.fillMaxSize(),
+            )
+        }
+    }
+}
+
 /**
  * HSV color picker dialog (hue / saturation / brightness sliders).
  * [onApply] applies the color and keeps the dialog open for further tweaks;
@@ -462,11 +561,12 @@ private fun ColorPickerDialog(
         text = {
             Column(modifier = Modifier.fillMaxWidth()) {
                 Box(
-                    modifier = Modifier
-                        .fillMaxWidth()
-                        .height(48.dp)
-                        .clip(RoundedCornerShape(8.dp))
-                        .background(color),
+                    modifier =
+                        Modifier
+                            .fillMaxWidth()
+                            .height(48.dp)
+                            .clip(RoundedCornerShape(8.dp))
+                            .background(color),
                 )
                 Spacer(modifier = Modifier.height(12.dp))
                 Slider(value = hue, onValueChange = { hue = it }, valueRange = 0f..360f)
@@ -505,11 +605,12 @@ private fun argbToHsv(argb: Int): FloatArray {
     val delta = max - min
     var hue = 0f
     if (delta != 0f) {
-        hue = when (max) {
-            r -> ((g - b) / delta) % 6f
-            g -> (b - r) / delta + 2f
-            else -> (r - g) / delta + 4f
-        }
+        hue =
+            when (max) {
+                r -> ((g - b) / delta) % 6f
+                g -> (b - r) / delta + 2f
+                else -> (r - g) / delta + 4f
+            }
         hue *= 60f
         if (hue < 0f) hue += 360f
     }
@@ -518,5 +619,4 @@ private fun argbToHsv(argb: Int): FloatArray {
 }
 
 /** File name from a path (no java.io.File in common code). */
-private fun fileNameOf(path: String): String =
-    path.substringAfterLast('/').ifEmpty { path.substringAfterLast('\\') }
\ No newline at end of file
+private fun fileNameOf(path: String): String = path.substringAfterLast('/').ifEmpty { path.substringAfterLast('\\') }
diff --git a/app/shared/src/commonMain/kotlin/iris/ui/theme/Backdrop.kt b/app/shared/src/commonMain/kotlin/iris/ui/theme/Backdrop.kt
new file mode 100644
index 0000000..0250a18
--- /dev/null
+++ b/app/shared/src/commonMain/kotlin/iris/ui/theme/Backdrop.kt
@@ -0,0 +1,40 @@
+package iris.ui.theme
+
+/**
+ * A bundled backdrop image shipped in the app (Android `assets/backdrops/`,
+ * desktop classpath `backdrops/`), loaded via [iris.platform.readBackdropBytes].
+ *
+ * Bundled backdrops are referenced in [UserTheme.backgroundImagePath] by the
+ * sentinel path `backdrop://<id>` (see [path]); user-picked images use a real
+ * file path. [DEFAULT] is the background for fresh installs.
+ */
+data class Backdrop(
+    val id: String,
+    val name: String,
+) {
+    /** Sentinel path stored in the theme for this bundled backdrop. */
+    val path: String get() = "backdrop://$id"
+
+    companion object {
+        const val PATH_PREFIX = "backdrop://"
+
+        val ALL: List<Backdrop> =
+            listOf(
+                Backdrop("pexels-yunszyveli-12368637", "Yun Syzveli"),
+                Backdrop("pexels-bogdankrupin-12049700", "Bogdan Krupin"),
+                Backdrop("pexels-bosichong-27940302", "Bosi Chong"),
+                Backdrop("pexels-farhan-najeer-644774196-32490483", "Farhan Najeer"),
+                Backdrop("pexels-soubhagya23-8060218", "Soubhagya"),
+                Backdrop("pexels-steve-29390703", "Steve"),
+            )
+
+        /** Default background for new chats / fresh installs. */
+        val DEFAULT: Backdrop = ALL.first { it.id == "pexels-yunszyveli-12368637" }
+
+        /** True when [path] references a bundled backdrop. */
+        fun isBackdropPath(path: String?): Boolean = !path.isNullOrBlank() && path.startsWith(PATH_PREFIX)
+
+        /** The bundled backdrop for a sentinel path, or null. */
+        fun fromPath(path: String?): Backdrop? = if (isBackdropPath(path)) ALL.firstOrNull { it.path == path } else null
+    }
+}
diff --git a/app/shared/src/commonMain/kotlin/iris/ui/theme/Theme.kt b/app/shared/src/commonMain/kotlin/iris/ui/theme/Theme.kt
index 9e2c096..f89e0a2 100644
--- a/app/shared/src/commonMain/kotlin/iris/ui/theme/Theme.kt
+++ b/app/shared/src/commonMain/kotlin/iris/ui/theme/Theme.kt
@@ -11,7 +11,9 @@ import androidx.compose.runtime.setValue
 import androidx.compose.runtime.staticCompositionLocalOf
 import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.graphics.ImageBitmap
+import iris.platform.decodeImageBytes
 import iris.platform.loadScaledImage
+import iris.platform.readBackdropBytes
 
 /**
  * Centralized palette (M7). Dark is the only theme; every screen reads colors
@@ -54,16 +56,17 @@ object IrisColors {
     val errorText = Color(0xFFFF8A80)
 }
 
-private val IrisDark = darkColorScheme(
-    background = IrisColors.background,
-    surface = IrisColors.surface,
-    onBackground = IrisColors.onBackground,
-    onSurface = IrisColors.onSurface,
-    onSurfaceVariant = IrisColors.textDim,
-    primary = IrisColors.primary,
-    onPrimary = Color.White,
-    error = IrisColors.statusRed,
-)
+private val IrisDark =
+    darkColorScheme(
+        background = IrisColors.background,
+        surface = IrisColors.surface,
+        onBackground = IrisColors.onBackground,
+        onSurface = IrisColors.onSurface,
+        onSurfaceVariant = IrisColors.textDim,
+        primary = IrisColors.primary,
+        onPrimary = Color.White,
+        error = IrisColors.statusRed,
+    )
 
 @Composable
 fun IrisTheme(content: @Composable () -> Unit) {
@@ -85,9 +88,11 @@ fun avatarColor(name: String): Color {
 data class UserTheme(
     val userBubbleColor: Int = DEFAULT_USER_BUBBLE,
     val agentBubbleColor: Int = DEFAULT_AGENT_BUBBLE,
-    val backgroundMode: BackgroundMode = BackgroundMode.Color,
+    // Fresh installs start with the default bundled backdrop (Settings →
+    // Appearance to change it).
+    val backgroundMode: BackgroundMode = BackgroundMode.Image,
     val backgroundColor: Int = DEFAULT_BACKGROUND,
-    val backgroundImagePath: String? = null,
+    val backgroundImagePath: String? = Backdrop.DEFAULT.path,
 ) {
     val userBubble: Color get() = Color(userBubbleColor)
     val agentBubble: Color get() = Color(agentBubbleColor)
@@ -114,8 +119,10 @@ fun Color.contrastText(): Color {
 
 /**
  * Decodes the theme's background image (image mode only), scaled to at most
- * 2048 px on the longest edge. Null in color mode or on decode failure — the
- * caller then falls back to the solid background color.
+ * 2048 px on the longest edge. Bundled backdrops (`backdrop://<id>`) are read
+ * from the app resources; anything else is a user-picked file path. Null in
+ * color mode or on decode failure — the caller then falls back to the solid
+ * background color.
  */
 @Composable
 fun rememberBackgroundImage(theme: UserTheme): ImageBitmap? {
@@ -123,7 +130,18 @@ fun rememberBackgroundImage(theme: UserTheme): ImageBitmap? {
     val wantImage = theme.backgroundMode == BackgroundMode.Image && !path.isNullOrBlank()
     var image by remember { mutableStateOf<ImageBitmap?>(null) }
     LaunchedEffect(wantImage, path) {
-        image = if (wantImage) loadScaledImage(path!!, 2048) else null
+        image =
+            if (!wantImage) {
+                null
+            } else {
+                val backdrop = Backdrop.fromPath(path)
+                val bytes = backdrop?.let { readBackdropBytes(it.id) }
+                if (bytes != null) {
+                    decodeImageBytes(bytes, 2048)
+                } else {
+                    loadScaledImage(path!!, 2048)
+                }
+            }
     }
     return image
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/desktopMain/kotlin/iris/platform/DesktopMedia.kt b/app/shared/src/desktopMain/kotlin/iris/platform/DesktopMedia.kt
index 5509e72..b99b023 100644
--- a/app/shared/src/desktopMain/kotlin/iris/platform/DesktopMedia.kt
+++ b/app/shared/src/desktopMain/kotlin/iris/platform/DesktopMedia.kt
@@ -1,5 +1,7 @@
 package iris.platform
 
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Row
@@ -8,8 +10,6 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.shape.RoundedCornerShape
-import androidx.compose.foundation.background
-import androidx.compose.foundation.clickable
 import androidx.compose.material3.Button
 import androidx.compose.material3.IconButton
 import androidx.compose.material3.Slider
@@ -31,17 +31,6 @@ import androidx.compose.ui.graphics.toComposeImageBitmap
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import iris.data.MediaItem
-import java.awt.image.BufferedImage
-import java.io.ByteArrayOutputStream
-import java.io.File
-import java.net.StandardProtocolFamily
-import java.net.UnixDomainSocketAddress
-import java.nio.ByteBuffer
-import java.nio.channels.SocketChannel
-import java.util.concurrent.TimeUnit
-import javax.imageio.ImageIO
-import javax.swing.JFileChooser
-import javax.swing.filechooser.FileNameExtensionFilter
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.withContext
@@ -53,6 +42,18 @@ import kotlinx.serialization.json.buildJsonArray
 import kotlinx.serialization.json.buildJsonObject
 import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
+import java.awt.image.BufferedImage
+import java.io.ByteArrayInputStream
+import java.io.ByteArrayOutputStream
+import java.io.File
+import java.net.StandardProtocolFamily
+import java.net.UnixDomainSocketAddress
+import java.nio.ByteBuffer
+import java.nio.channels.SocketChannel
+import java.util.concurrent.TimeUnit
+import javax.imageio.ImageIO
+import javax.swing.JFileChooser
+import javax.swing.filechooser.FileNameExtensionFilter
 import kotlin.random.Random
 
 /**
@@ -63,9 +64,10 @@ import kotlin.random.Random
 actual fun MediaFilePicker(onPicked: (PickedFile?) -> Unit) {
     var busy by remember { mutableStateOf(false) }
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .padding(16.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .padding(16.dp),
     ) {
         Text("Attach a file:", fontSize = 13.sp)
         Spacer(modifier = Modifier.height(8.dp))
@@ -98,9 +100,10 @@ private fun pickFile(): PickedFile? {
 @Composable
 actual fun ImageFilePicker(onPicked: (PickedFile?) -> Unit) {
     Button(onClick = {
-        val chooser = JFileChooser().apply {
-            fileFilter = FileNameExtensionFilter("Images", "jpg", "jpeg", "png", "webp", "bmp", "gif")
-        }
+        val chooser =
+            JFileChooser().apply {
+                fileFilter = FileNameExtensionFilter("Images", "jpg", "jpeg", "png", "webp", "bmp", "gif")
+            }
         if (chooser.showOpenDialog(null) != JFileChooser.APPROVE_OPTION) {
             onPicked(null)
             return@Button
@@ -151,62 +154,110 @@ actual fun mediaCacheBaseDir(): String {
     return dir.absolutePath
 }
 
-actual suspend fun loadMediaImage(path: String): ImageBitmap? = withContext(Dispatchers.IO) {
+actual suspend fun loadMediaImage(path: String): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            val img = ImageIO.read(File(path)) ?: return@withContext null
+            img.toComposeImageBitmap()
+        } catch (_: Exception) {
+            null
+        }
+    }
+
+actual suspend fun loadScaledImage(
+    path: String,
+    maxSize: Int,
+): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            val img = ImageIO.read(File(path)) ?: return@withContext null
+            val scale = (maxSize.toFloat() / maxOf(img.width, img.height)).coerceAtMost(1f)
+            if (scale >= 1f) {
+                img.toComposeImageBitmap()
+            } else {
+                val sw = (img.width * scale).toInt().coerceAtLeast(1)
+                val sh = (img.height * scale).toInt().coerceAtLeast(1)
+                val scaled = BufferedImage(sw, sh, BufferedImage.TYPE_INT_ARGB)
+                val g = scaled.createGraphics()
+                g.drawImage(img, 0, 0, sw, sh, null)
+                g.dispose()
+                scaled.toComposeImageBitmap()
+            }
+        } catch (_: Exception) {
+            null
+        }
+    }
+
+actual suspend fun decodeImageBytes(
+    bytes: ByteArray,
+    maxSize: Int,
+): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            val img = ImageIO.read(ByteArrayInputStream(bytes)) ?: return@withContext null
+            val scale = (maxSize.toFloat() / maxOf(img.width, img.height)).coerceAtMost(1f)
+            if (scale >= 1f) {
+                img.toComposeImageBitmap()
+            } else {
+                val sw = (img.width * scale).toInt().coerceAtLeast(1)
+                val sh = (img.height * scale).toInt().coerceAtLeast(1)
+                val scaled = BufferedImage(sw, sh, BufferedImage.TYPE_INT_ARGB)
+                val g = scaled.createGraphics()
+                g.drawImage(img, 0, 0, sw, sh, null)
+                g.dispose()
+                scaled.toComposeImageBitmap()
+            }
+        } catch (_: Exception) {
+            null
+        }
+    }
+
+actual fun readBackdropBytes(id: String): ByteArray? =
     try {
-        val img = ImageIO.read(File(path)) ?: return@withContext null
-        img.toComposeImageBitmap()
-    } catch (_: Exception) {
+        // Top-level function: no `javaClass`, so anchor the classpath lookup to a
+        // class in this module (PickedFile, same package).
+        PickedFile::class.java.getResourceAsStream("/backdrops/$id.jpg")?.use { it.readBytes() }
+    } catch (e: Exception) {
         null
     }
-}
 
-actual suspend fun loadScaledImage(path: String, maxSize: Int): ImageBitmap? = withContext(Dispatchers.IO) {
-    try {
-        val img = ImageIO.read(File(path)) ?: return@withContext null
-        val scale = (maxSize.toFloat() / maxOf(img.width, img.height)).coerceAtMost(1f)
-        if (scale >= 1f) {
-            img.toComposeImageBitmap()
-        } else {
+actual suspend fun encodeImageAsBase64(
+    path: String,
+    maxSize: Int,
+): String? =
+    withContext(Dispatchers.IO) {
+        try {
+            val img = ImageIO.read(File(path)) ?: return@withContext null
+            val scale = (maxSize.toFloat() / maxOf(img.width, img.height)).coerceAtMost(1f)
             val sw = (img.width * scale).toInt().coerceAtLeast(1)
             val sh = (img.height * scale).toInt().coerceAtLeast(1)
             val scaled = BufferedImage(sw, sh, BufferedImage.TYPE_INT_ARGB)
             val g = scaled.createGraphics()
             g.drawImage(img, 0, 0, sw, sh, null)
             g.dispose()
-            scaled.toComposeImageBitmap()
+            val baos = ByteArrayOutputStream()
+            ImageIO.write(scaled, "png", baos)
+            java.util.Base64
+                .getEncoder()
+                .encodeToString(baos.toByteArray())
+        } catch (_: Exception) {
+            null
         }
-    } catch (_: Exception) {
-        null
     }
-}
 
-actual suspend fun encodeImageAsBase64(path: String, maxSize: Int): String? = withContext(Dispatchers.IO) {
-    try {
-        val img = ImageIO.read(File(path)) ?: return@withContext null
-        val scale = (maxSize.toFloat() / maxOf(img.width, img.height)).coerceAtMost(1f)
-        val sw = (img.width * scale).toInt().coerceAtLeast(1)
-        val sh = (img.height * scale).toInt().coerceAtLeast(1)
-        val scaled = BufferedImage(sw, sh, BufferedImage.TYPE_INT_ARGB)
-        val g = scaled.createGraphics()
-        g.drawImage(img, 0, 0, sw, sh, null)
-        g.dispose()
-        val baos = ByteArrayOutputStream()
-        ImageIO.write(scaled, "png", baos)
-        java.util.Base64.getEncoder().encodeToString(baos.toByteArray())
-    } catch (_: Exception) {
-        null
+actual suspend fun decodeBase64Image(base64: String): ImageBitmap? =
+    withContext(Dispatchers.IO) {
+        try {
+            val bytes =
+                java.util.Base64
+                    .getDecoder()
+                    .decode(base64)
+            val img = ImageIO.read(java.io.ByteArrayInputStream(bytes)) ?: return@withContext null
+            img.toComposeImageBitmap()
+        } catch (_: Exception) {
+            null
+        }
     }
-}
-
-actual suspend fun decodeBase64Image(base64: String): ImageBitmap? = withContext(Dispatchers.IO) {
-    try {
-        val bytes = java.util.Base64.getDecoder().decode(base64)
-        val img = ImageIO.read(java.io.ByteArrayInputStream(bytes)) ?: return@withContext null
-        img.toComposeImageBitmap()
-    } catch (_: Exception) {
-        null
-    }
-}
 
 /**
  * M6: inline media playback backed by mpv (docs/11 §11.2).
@@ -219,7 +270,10 @@ actual suspend fun decodeBase64Image(base64: String): ImageBitmap? = withContext
  * - no mpv on PATH: an info chip (the WebView fallback is a stretch goal).
  */
 @Composable
-actual fun MediaPlayerView(media: MediaItem, modifier: Modifier) {
+actual fun MediaPlayerView(
+    media: MediaItem,
+    modifier: Modifier,
+) {
     val path = media.localPath
     if (path == null || !File(path).exists()) {
         Box(modifier = modifier.fillMaxWidth(), contentAlignment = Alignment.Center) {
@@ -246,7 +300,12 @@ private object Mpv {
     val available: Boolean by lazy {
         try {
             val p = ProcessBuilder("which", "mpv").redirectErrorStream(true).start()
-            val found = p.inputStream.bufferedReader().readText().trim().isNotBlank()
+            val found =
+                p.inputStream
+                    .bufferedReader()
+                    .readText()
+                    .trim()
+                    .isNotBlank()
             p.waitFor(2, TimeUnit.SECONDS)
             found
         } catch (_: Exception) {
@@ -256,7 +315,10 @@ private object Mpv {
 }
 
 @Composable
-private fun AudioPlayer(media: MediaItem, path: String) {
+private fun AudioPlayer(
+    media: MediaItem,
+    path: String,
+) {
     val session = remember(path) { MpvAudioSession(path) }
     var paused by remember { mutableStateOf(true) }
     var position by remember { mutableStateOf(0.0) }
@@ -278,11 +340,12 @@ private fun AudioPlayer(media: MediaItem, path: String) {
     }
 
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(10.dp))
-            .background(Color(0xFF20242E))
-            .padding(10.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(10.dp))
+                .background(Color(0xFF20242E))
+                .padding(10.dp),
     ) {
         Text(media.filename, fontSize = 12.sp, maxLines = 1)
         Spacer(modifier = Modifier.height(6.dp))
@@ -309,14 +372,18 @@ private fun AudioPlayer(media: MediaItem, path: String) {
 }
 
 @Composable
-private fun VideoPlayer(media: MediaItem, path: String) {
+private fun VideoPlayer(
+    media: MediaItem,
+    path: String,
+) {
     var process by remember { mutableStateOf<Process?>(null) }
     Column(
-        modifier = Modifier
-            .fillMaxWidth()
-            .clip(RoundedCornerShape(10.dp))
-            .background(Color(0xFF20242E))
-            .padding(10.dp),
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clip(RoundedCornerShape(10.dp))
+                .background(Color(0xFF20242E))
+                .padding(10.dp),
     ) {
         Text(media.filename, fontSize = 12.sp, maxLines = 1)
         Spacer(modifier = Modifier.height(6.dp))
@@ -352,7 +419,9 @@ private fun fmtTime(sec: Double): String {
  * An mpv process + its JSON IPC socket (unix domain). Commands carry a
  * [requestId] so responses can be matched and async events skipped.
  */
-private class MpvAudioSession(private val path: String) {
+private class MpvAudioSession(
+    private val path: String,
+) {
     private var process: Process? = null
     private var channel: SocketChannel? = null
     private val socketPath =
@@ -362,10 +431,15 @@ private class MpvAudioSession(private val path: String) {
 
     fun start() {
         try {
-            process = ProcessBuilder(
-                "mpv", "--no-video", "--really-quiet", "--no-terminal",
-                "--input-ipc-server=$socketPath", path,
-            ).redirectErrorStream(true).start()
+            process =
+                ProcessBuilder(
+                    "mpv",
+                    "--no-video",
+                    "--really-quiet",
+                    "--no-terminal",
+                    "--input-ipc-server=$socketPath",
+                    path,
+                ).redirectErrorStream(true).start()
             connectIpc()
         } catch (_: Exception) {
         }
@@ -406,9 +480,24 @@ private class MpvAudioSession(private val path: String) {
                 } catch (_: Exception) {
                 }
             }
-            answers["p1"]?.get("data")?.jsonPrimitive?.content?.toDoubleOrNull()?.let { pos = it }
-            answers["p2"]?.get("data")?.jsonPrimitive?.content?.toDoubleOrNull()?.let { dur = it }
-            answers["p3"]?.get("data")?.jsonPrimitive?.content?.toBooleanStrictOrNull()?.let { pause = it }
+            answers["p1"]
+                ?.get("data")
+                ?.jsonPrimitive
+                ?.content
+                ?.toDoubleOrNull()
+                ?.let { pos = it }
+            answers["p2"]
+                ?.get("data")
+                ?.jsonPrimitive
+                ?.content
+                ?.toDoubleOrNull()
+                ?.let { dur = it }
+            answers["p3"]
+                ?.get("data")
+                ?.jsonPrimitive
+                ?.content
+                ?.toBooleanStrictOrNull()
+                ?.let { pause = it }
         } catch (_: Exception) {
         }
         return Triple(pos, dur, pause)
@@ -440,12 +529,16 @@ private class MpvAudioSession(private val path: String) {
         }
     }
 
-    private fun send(cmd: List<String>, requestId: String?) {
+    private fun send(
+        cmd: List<String>,
+        requestId: String?,
+    ) {
         val ch = channel ?: return
-        val obj = buildJsonObject {
-            put("command", buildJsonArray { cmd.forEach { add(JsonPrimitive(it)) } })
-            requestId?.let { put("request_id", JsonPrimitive(it)) }
-        }
+        val obj =
+            buildJsonObject {
+                put("command", buildJsonArray { cmd.forEach { add(JsonPrimitive(it)) } })
+                requestId?.let { put("request_id", JsonPrimitive(it)) }
+            }
         val bytes = (obj.toString() + "\n").toByteArray(Charsets.UTF_8)
         ch.write(ByteBuffer.wrap(bytes))
     }
@@ -471,15 +564,25 @@ private class MpvAudioSession(private val path: String) {
     }
 }
 
-actual fun openDocument(path: String, mime: String) {
+actual fun openDocument(
+    path: String,
+    mime: String,
+) {
     try {
         val os = System.getProperty("os.name").lowercase()
         when {
-            os.contains("mac") -> ProcessBuilder("open", path).start()
-            os.contains("win") ->
+            os.contains("mac") -> {
+                ProcessBuilder("open", path).start()
+            }
+
+            os.contains("win") -> {
                 ProcessBuilder("rundll32", "url.dll,FileProtocolHandler", path).start()
-            else -> ProcessBuilder("xdg-open", path).start()
+            }
+
+            else -> {
+                ProcessBuilder("xdg-open", path).start()
+            }
         }
     } catch (_: Exception) {
     }
-}
\ No newline at end of file
+}
diff --git a/app/shared/src/desktopMain/kotlin/iris/platform/DesktopSecureStore.kt b/app/shared/src/desktopMain/kotlin/iris/platform/DesktopSecureStore.kt
index baba4ad..7ef3b67 100644
--- a/app/shared/src/desktopMain/kotlin/iris/platform/DesktopSecureStore.kt
+++ b/app/shared/src/desktopMain/kotlin/iris/platform/DesktopSecureStore.kt
@@ -2,14 +2,16 @@ package iris.platform
 
 import iris.data.SecureStore
 import iris.protocol.IrisJson
+import iris.ui.theme.Backdrop
+import iris.ui.theme.BackgroundMode
 import iris.ui.theme.UserTheme
+import kotlinx.serialization.Serializable
 import java.io.File
 import java.security.SecureRandom
 import java.util.UUID
 import javax.crypto.Cipher
 import javax.crypto.spec.GCMParameterSpec
 import javax.crypto.spec.SecretKeySpec
-import kotlinx.serialization.Serializable
 
 /**
  * M6: desktop pairing storage (docs/11 §11.2).
@@ -41,9 +43,9 @@ class DesktopSecureStore : SecureStore {
         val reasoningAutoCollapse: Boolean = true,
         val userBubbleColor: Int = UserTheme.DEFAULT_USER_BUBBLE,
         val agentBubbleColor: Int = UserTheme.DEFAULT_AGENT_BUBBLE,
-        val backgroundMode: String = "color",
+        val backgroundMode: String = BackgroundMode.Image.name.lowercase(),
         val backgroundColor: Int = UserTheme.DEFAULT_BACKGROUND,
-        val backgroundImagePath: String = "",
+        val backgroundImagePath: String = Backdrop.DEFAULT.path,
         val fontSizeScale: Float = 1.0f,
     )
 
@@ -53,11 +55,12 @@ class DesktopSecureStore : SecureStore {
 
     private fun migrateLegacy() {
         if (!legacyFile.exists()) return
-        val legacy = try {
-            IrisJson.instance.decodeFromString(PairingData.serializer(), legacyFile.readText())
-        } catch (_: Exception) {
-            null
-        }
+        val legacy =
+            try {
+                IrisJson.instance.decodeFromString(PairingData.serializer(), legacyFile.readText())
+            } catch (_: Exception) {
+                null
+            }
         if (legacy != null) {
             val s = load()
             save(
@@ -108,7 +111,13 @@ class DesktopSecureStore : SecureStore {
         get() {
             val d = load()
             if (d.deviceId.isNotBlank()) return d.deviceId
-            val id = "dev_" + UUID.randomUUID().toString().replace("-", "").take(16)
+            val id =
+                "dev_" +
+                    UUID
+                        .randomUUID()
+                        .toString()
+                        .replace("-", "")
+                        .take(16)
             save(d.copy(deviceId = id))
             return id
         }
@@ -214,7 +223,10 @@ class DesktopSecureStore : SecureStore {
             save(d.copy(fontSizeScale = value))
         }
 
-    override fun savePairing(url: String, token: String) {
+    override fun savePairing(
+        url: String,
+        token: String,
+    ) {
         val d = load()
         save(d.copy(serverUrl = url.trim()))
         if (token.isBlank()) secret.clear() else secret.write(token.trim())
@@ -243,7 +255,9 @@ private data class PairingData(
  * Token storage: OS keyring when available, else an AES-GCM encrypted file.
  * All backend failures degrade to the encrypted file (never plaintext).
  */
-private class SecretBackend(private val baseDir: File) {
+private class SecretBackend(
+    private val baseDir: File,
+) {
     private val encFile = File(baseDir, "pairing.enc")
     private val keyFile = File(baseDir, ".key")
     private val keyring: KeyringBackend? = KeyringBackend().takeIf { it.available }
@@ -318,32 +332,49 @@ private class KeyringBackend {
 
     /** macOS Keychain (`security`) or Linux Secret Service (`secret-tool`). */
     val available: Boolean by lazy {
-        if (isMac) true
-        else if (isLinux) which("secret-tool") != null
-        else false
+        if (isMac) {
+            true
+        } else if (isLinux) {
+            which("secret-tool") != null
+        } else {
+            false
+        }
     }
 
-    fun read(): String? = try {
-        if (isMac) {
-            out(listOf("security", "find-generic-password", "-a", "iris", "-s", "iris-gateway-token", "-w"))
-        } else {
-            out(listOf("secret-tool", "lookup", "app", "iris"))
+    fun read(): String? =
+        try {
+            if (isMac) {
+                out(listOf("security", "find-generic-password", "-a", "iris", "-s", "iris-gateway-token", "-w"))
+            } else {
+                out(listOf("secret-tool", "lookup", "app", "iris"))
+            }
+        } catch (_: Exception) {
+            null
         }
-    } catch (_: Exception) {
-        null
-    }
 
     fun write(value: String) {
         try {
             if (isMac) {
                 ProcessBuilder(
-                    "security", "add-generic-password", "-U",
-                    "-a", "iris", "-s", "iris-gateway-token", "-w", value,
+                    "security",
+                    "add-generic-password",
+                    "-U",
+                    "-a",
+                    "iris",
+                    "-s",
+                    "iris-gateway-token",
+                    "-w",
+                    value,
                 ).inheritIO().start().waitFor()
             } else {
                 ProcessBuilder(
-                    "secret-tool", "store", "--label=Iris gateway token",
-                    "app", "iris", "token", value,
+                    "secret-tool",
+                    "store",
+                    "--label=Iris gateway token",
+                    "app",
+                    "iris",
+                    "token",
+                    value,
                 ).inheritIO().start().waitFor()
             }
         } catch (_: Exception) {
@@ -354,12 +385,19 @@ private class KeyringBackend {
         try {
             if (isMac) {
                 ProcessBuilder(
-                    "security", "delete-generic-password",
-                    "-a", "iris", "-s", "iris-gateway-token",
+                    "security",
+                    "delete-generic-password",
+                    "-a",
+                    "iris",
+                    "-s",
+                    "iris-gateway-token",
                 ).inheritIO().start().waitFor()
             } else {
                 ProcessBuilder(
-                    "secret-tool", "clear", "app", "iris",
+                    "secret-tool",
+                    "clear",
+                    "app",
+                    "iris",
                 ).inheritIO().start().waitFor()
             }
         } catch (_: Exception) {
@@ -368,17 +406,26 @@ private class KeyringBackend {
 
     private fun out(cmd: List<String>): String? {
         val p = ProcessBuilder(cmd).redirectErrorStream(true).start()
-        val text = p.inputStream.bufferedReader().readText().trim()
+        val text =
+            p.inputStream
+                .bufferedReader()
+                .readText()
+                .trim()
         p.waitFor()
         return text.ifBlank { null }
     }
 
-    private fun which(bin: String): String? = try {
-        val p = ProcessBuilder("which", bin).redirectErrorStream(true).start()
-        val text = p.inputStream.bufferedReader().readText().trim()
-        p.waitFor()
-        text.ifBlank { null }
-    } catch (_: Exception) {
-        null
-    }
-}
\ No newline at end of file
+    private fun which(bin: String): String? =
+        try {
+            val p = ProcessBuilder("which", bin).redirectErrorStream(true).start()
+            val text =
+                p.inputStream
+                    .bufferedReader()
+                    .readText()
+                    .trim()
+            p.waitFor()
+            text.ifBlank { null }
+        } catch (_: Exception) {
+            null
+        }
+}
diff --git a/app/shared/src/desktopMain/kotlin/iris/platform/Platform.kt b/app/shared/src/desktopMain/kotlin/iris/platform/Platform.kt
index d648810..564d877 100644
--- a/app/shared/src/desktopMain/kotlin/iris/platform/Platform.kt
+++ b/app/shared/src/desktopMain/kotlin/iris/platform/Platform.kt
@@ -1,3 +1,3 @@
 package iris.platform
 
-actual val isDesktop: Boolean = true
\ No newline at end of file
+actual val isDesktop: Boolean = true
diff --git a/app/shared/src/desktopMain/resources/backdrops/pexels-bogdankrupin-12049700.jpg b/app/shared/src/desktopMain/resources/backdrops/pexels-bogdankrupin-12049700.jpg
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