Composer auto-grow (1→5 lines) + in-field attach; settings screen + persisted prefs

- Composer input starts at one line and auto-grows up to 5 lines (then scrolls),
  measured via onTextLayout; attach (paperclip) moved inside the field, right of
  the text, per the Telegram reference.

- New SettingsScreen (drawer/rail entry) for Threads + Tool detail; both now
  persist via SecureStore (Android prefs / desktop JSON).

- Add AGENTS.md; rename reference screenshot to telegram_screenshot_reference.jpg.

AGENTS.md

@@ -0,0 +1,39 @@
+# AGENTS.md
+
+## Hard rules
+
+- `hermes-agent/` is a **read-only research reference** (git-ignored). Never commit, push, or modify it — a pre-commit hook (`scripts/guard_hermes_agent.sh --staged`) fails any commit that stages it. Never modify hermes core; we only install our plugin into the live hermes home.
+- The plugin is installed by symlink: `~/.hermes/plugins/android` → `<repo>/gateway-plugin` (already set up on this machine).
+
+## Layout
+
+- `gateway-plugin/` — Python hermes platform plugin (`android`). No build step, zero new deps (stdlib + hermes-provided `websockets`/`httpx`). `protocol.py` is the frame source of truth, mirrored in `app/shared/.../protocol/Protocol.kt` and `docs/protocol/frames.schema.json`.
+- `app/` — one Compose Multiplatform Gradle project: `:shared` (KMP, most of the code; `jvmMain` is shared by the android and desktop targets since both are JVM-based), `:androidApp` (thin shell, package `dev.iris.app`), `:desktopApp` (thin shell).
+- `docs/` — numbered reference library; read `docs/00-overview.md` first. Locked decisions: `docs/16-open-questions.md`.
+
+## Commands
+
+- `hermes` is **not on PATH**: use `hermes-agent/.venv/bin/hermes` (venv from `cd hermes-agent && uv sync`).
+- Gateway: `hermes gateway setup` (one-time; generates `ANDROID_TOKEN` in `~/.hermes/.env`, prints the token only once) → `hermes gateway` (run) → `hermes gateway status`.
+- Android: check the device is connected first (`adb devices` → `a5ca2a4b` listed as `device`); then `cd app && ./gradlew :androidApp:installDebug` to install on the phone and live-verify changes (launch/screenshot: see ADB below).
+- Desktop: `cd app && ./gradlew :desktopApp:run`; packaging: `:desktopApp:jpackage` (app-image; `-PjpackageType=deb` for a .deb).
+- Python tests — **never bare `pytest`**: `cd hermes-agent && scripts/run_tests.sh tests/gateway/test_android.py` (no args = full suite).
+- Kotlin tests: `cd app && ./gradlew :shared:testDebugUnitTest` / `:shared:desktopTest` (no test sources exist yet).
+- WS probe (gateway must be running): `hermes-agent/.venv/bin/python gateway-plugin/tests/ws_probe.py --token <ANDROID_TOKEN> --send "hello"` — assertion flags documented in `gateway-plugin/tests/README.md`.
+- E2E driver (gateway must be running; it never starts/stops it): `hermes-agent/.venv/bin/python gateway-plugin/tests/e2e.py`.
+
+## Environment / pairing quirks
+
+- Pairing token: `ANDROID_TOKEN` in `~/.hermes/.env`. The app has **no QR scanner** — pairing is manual URL + token entry.
+- WS default bind is `127.0.0.1`; for a phone on the LAN set `ANDROID_WS_HOST` to the gateway's LAN IP.
+- `app/local.properties` (`sdk.dir`) is git-ignored and required for Android builds.
+- `google-services.json` is optional: without it FCM is inert and ntfy is the push path. Public ntfy.sh SSE is flaky — self-host ntfy.
+- JDK 17; no system Gradle — always the wrapper (`./gradlew`).
+- Desktop jpackage on Linux/JDK 17 prints a non-fatal `pure virtual method called` (JDK-8348560); the app works.
+
+## Testing quirks
+
+- `hermes-agent/tests/gateway/test_android.py` is a thin mirror that imports the **live `gateway-plugin/` package from this repo** (override with `ANDROID_PLUGIN_DIR`); HERMES_HOME is sandboxed per-test by the conftest. Tests must never touch the real `~/.hermes`.
+- e2e scenarios 3 (reasoning) and 5 (commentary) are model-dependent → SKIP; 11 (push) and 12 (reconnect) are PARTIAL by design.
+- ADB: launch `adb shell am start -n dev.iris.app/.MainActivity`; reset pairing state `adb shell pm clear dev.iris.app`; screenshot `adb exec-out screencap -p > /tmp/shot.png`.
+- Gateway logs: `~/.hermes/logs/gateway.log` or `hermes logs --follow`.

app/shared/src/androidMain/kotlin/iris/platform/AndroidSecureStore.kt

@@ -97,6 +97,14 @@ class AndroidSecureStore(context: Context) : SecureStore {
         get() = prefs.getString(KEY_NTFY_SERVER, "").orEmpty()
         set(value) = prefs.edit().putString(KEY_NTFY_SERVER, value).apply()
 
+    override var threadsEnabled: Boolean
+        get() = prefs.getBoolean(KEY_THREADS_ENABLED, false)
+        set(value) = prefs.edit().putBoolean(KEY_THREADS_ENABLED, value).apply()
+
+    override var toolDetail: String
+        get() = prefs.getString(KEY_TOOL_DETAIL, "truncated").orEmpty().ifBlank { "truncated" }
+        set(value) = prefs.edit().putString(KEY_TOOL_DETAIL, value).apply()
+
     override fun savePairing(url: String, token: String) {
         serverUrl = url
         this.token = token
@@ -116,5 +124,7 @@ class AndroidSecureStore(context: Context) : SecureStore {
         const val KEY_FCM_TOKEN = "fcm_token"
         const val KEY_NTFY_TOPIC = "ntfy_topic"
         const val KEY_NTFY_SERVER = "ntfy_server"
+        const val KEY_THREADS_ENABLED = "threads_enabled"
+        const val KEY_TOOL_DETAIL = "tool_detail"
     }
 }

app/shared/src/commonMain/kotlin/iris/data/SecureStore.kt

@@ -30,6 +30,12 @@ interface SecureStore {
     /** ntfy server URL (M5; from hello.ack server_caps; default ntfy.sh). */
     var ntfyServer: String
 
+    /** UI setting: show threads (topics) in the chat view. */
+    var threadsEnabled: Boolean
+
+    /** UI setting: tool verbosity — "everything" / "truncated" / "nothing". */
+    var toolDetail: String
+
     fun savePairing(url: String, token: String)
     fun clear()
 }

app/shared/src/commonMain/kotlin/iris/state/IrisController.kt

@@ -80,8 +80,9 @@ class IrisController(
     private val _typing = MutableStateFlow(false)
     val typing: StateFlow<Boolean> = _typing.asStateFlow()
 
-    /** Tool-card verbosity (M2). NOTHING suppresses tool cards entirely. */
+    /** Tool-card verbosity (M2). NOTHING suppresses tool cards entirely.
-    private val _toolDetail = MutableStateFlow(ToolDetail.TRUNCATED)
+     *  Persisted (Settings → "Tool detail"). */
+    private val _toolDetail = MutableStateFlow(ToolDetail.fromName(store.toolDetail))
     val toolDetail: StateFlow<ToolDetail> = _toolDetail.asStateFlow()
 
     fun cycleToolDetail() {
@@ -90,6 +91,13 @@ class IrisController(
             ToolDetail.TRUNCATED -> ToolDetail.NOTHING
             ToolDetail.NOTHING -> ToolDetail.EVERYTHING
         }
+        store.toolDetail = _toolDetail.value.name.lowercase()
+    }
+
+    fun setToolDetail(detail: ToolDetail) {
+        if (detail == _toolDetail.value) return
+        _toolDetail.value = detail
+        store.toolDetail = detail.name.lowercase()
     }
 
     /** Home channel id (from hello.ack; default until then). */
@@ -101,11 +109,13 @@ class IrisController(
     val gatewayStatus: StateFlow<String?> = _gatewayStatus.asStateFlow()
 
     // ── M3: threads toggle (per-app for now; per-channel lands later) ─────
-    private val _threadsEnabled = MutableStateFlow(false)
+    // Persisted (Settings → "Threads").
+    private val _threadsEnabled = MutableStateFlow(store.threadsEnabled)
     val threadsEnabled: StateFlow<Boolean> = _threadsEnabled.asStateFlow()
 
     fun toggleThreads() {
         _threadsEnabled.value = !_threadsEnabled.value
+        store.threadsEnabled = _threadsEnabled.value
     }
 
     // ── M3: search state ──────────────────────────────────────────────────
@@ -487,4 +497,11 @@ enum class ToolDetail {
     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
+    }
 }

app/shared/src/commonMain/kotlin/iris/ui/screens/ChatScreen.kt

@@ -41,6 +41,7 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.ModalDrawerSheet
 import androidx.compose.material3.ModalNavigationDrawer
+import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Text
 import androidx.compose.material3.TextButton
@@ -49,6 +50,7 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableFloatStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -70,6 +72,7 @@ import androidx.compose.ui.input.key.onPreviewKeyEvent
 import androidx.compose.ui.input.key.type
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.platform.LocalClipboardManager
+import androidx.compose.ui.platform.LocalDensity
 import androidx.compose.ui.platform.LocalFocusManager
 import androidx.compose.ui.text.AnnotatedString
 import androidx.compose.ui.text.font.FontFamily
@@ -107,7 +110,7 @@ import iris.util.localDayKey
 import kotlinx.coroutines.launch
 
 /**
- * Chat screen (M3): channel drawer + thread toggle + topic switcher + search,
+ * Chat screen (M3): channel drawer + topic switcher + search + settings,
  * on top of the M2 message list / composer. Messages are shown for the current
  * lane (a channel's flat lane, or a specific thread).
  */
@@ -132,6 +135,7 @@ fun ChatScreen(controller: IrisController) {
     var showNewChannel by remember { mutableStateOf(false) }
     var showNewThread by remember { mutableStateOf(false) }
     var showPicker by remember { mutableStateOf(false) }
+    var showSettings by remember { mutableStateOf(false) }
     val attachments by controller.attachments.collectAsState()
     val banners by controller.banners.collectAsState()
     val drawerState = rememberDrawerState(DrawerValue.Closed)
@@ -174,7 +178,7 @@ fun ChatScreen(controller: IrisController) {
             if (e.type != KeyEventType.KeyDown) return@onPreviewKeyEvent false
             val ctrlOrMeta = e.isCtrlPressed || e.isMetaPressed
             val overlayOpen =
-                showSearch || showPicker || showPalette || showNewChannel || showNewThread
+                showSearch || showPicker || showPalette || showNewChannel || showNewThread || showSettings
             when {
                 ctrlOrMeta && e.key == Key.N -> { showNewChannel = true; true }
                 ctrlOrMeta && e.key == Key.T -> { showNewThread = true; true }
@@ -186,6 +190,7 @@ fun ChatScreen(controller: IrisController) {
                     showPalette = false
                     showNewChannel = false
                     showNewThread = false
+                    showSettings = false
                     true
                 }
                 e.key == Key.Slash && !composerFocused && !overlayOpen -> {
@@ -231,12 +236,6 @@ fun ChatScreen(controller: IrisController) {
                         HeaderIconButton(onClick = { showSearch = true }) {
                             Text("🔍", fontSize = 16.sp)
                         }
-                        HeaderIconButton(onClick = { controller.toggleThreads() }) {
-                            Text(if (threadsEnabled) "🧵✓" else "🧵", fontSize = 16.sp)
-                        }
-                        TextButton(onClick = { controller.cycleToolDetail() }) {
-                            Text("tools: ${toolDetail.label}", fontSize = 11.sp)
-                        }
                         if (isDesktop) {
                             IconButton(onClick = { showInspector = !showInspector }) {
                                 Box(
@@ -290,12 +289,6 @@ fun ChatScreen(controller: IrisController) {
                             HeaderIconButton(onClick = { showSearch = true }) {
                                 Text("🔍", fontSize = 16.sp)
                             }
-                            HeaderIconButton(onClick = { controller.toggleThreads() }) {
-                                Text(if (threadsEnabled) "🧵✓" else "🧵", fontSize = 16.sp)
-                            }
-                            TextButton(onClick = { controller.cycleToolDetail() }) {
-                                Text("tools: ${toolDetail.label}", fontSize = 11.sp)
-                            }
                             if (isDesktop) {
                                 IconButton(onClick = { showInspector = !showInspector }) {
                                     Box(
@@ -438,6 +431,8 @@ fun ChatScreen(controller: IrisController) {
 
             // Composer (M7: rounded pill + accent circular send button)
             val canSend = input.isNotBlank() || attachments.any { it.mediaRef != null && it.error == null }
+            val layoutDensity = LocalDensity.current.density
+            var textHeightPx by remember { mutableFloatStateOf(0f) }
             Row(
                 modifier = Modifier
                     .fillMaxWidth()
@@ -447,15 +442,32 @@ fun ChatScreen(controller: IrisController) {
                     .padding(horizontal = 6.dp, vertical = 4.dp),
                 verticalAlignment = Alignment.CenterVertically,
             ) {
-                IconButton(onClick = { showPicker = true }) {
+                Row(
-                    Text("📎", fontSize = 18.sp)
-                }
-                Box(
                     modifier = Modifier
                         .weight(1f)
-                        .heightIn(min = 40.dp, max = 160.dp)
                         .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",
@@ -464,17 +476,10 @@ fun ChatScreen(controller: IrisController) {
                                 modifier = Modifier.align(Alignment.TopStart),
                             )
                         }
-                    BasicTextField(
+                    }
-                        value = input,
+                    IconButton(onClick = { showPicker = true }) {
-                        onValueChange = { input = it },
+                        Text("📎", fontSize = 18.sp)
-                        modifier = Modifier
+                    }
-                            .fillMaxSize()
-                            .focusRequester(composerFocusRequester)
-                            .onFocusChanged { composerFocused = it.isFocused },
-                        textStyle = MaterialTheme.typography.bodyLarge.copy(color = IrisColors.onSurface),
-                        keyboardOptions = KeyboardOptions(imeAction = ImeAction.Send),
-                        keyboardActions = KeyboardActions(onSend = { doSend() }),
-                    )
                 }
                 Box(
                     modifier = Modifier
@@ -537,6 +542,7 @@ fun ChatScreen(controller: IrisController) {
                     onNewChannel = { showNewChannel = true },
                     onSetDefault = { ch -> controller.setDefaultChannel(ch.chatId) },
                     onDelete = { ch -> controller.deleteChannel(ch.chatId) },
+                    onOpenSettings = { showSettings = true },
                 )
                 Box(modifier = Modifier.width(1.dp).fillMaxHeight().background(IrisColors.divider))
                 Box(modifier = Modifier.weight(1f).fillMaxHeight()) {
@@ -550,8 +556,6 @@ fun ChatScreen(controller: IrisController) {
                         currentChannel = currentChannel,
                         threads = threads,
                         items = items,
-                        toolDetail = toolDetail,
-                        threadsEnabled = threadsEnabled,
                     )
                 }
             }
@@ -574,6 +578,10 @@ fun ChatScreen(controller: IrisController) {
                             },
                             onSetDefault = { ch -> controller.setDefaultChannel(ch.chatId) },
                             onDelete = { ch -> controller.deleteChannel(ch.chatId) },
+                            onOpenSettings = {
+                                showSettings = true
+                                drawerScope.launch { drawerState.close() }
+                            },
                         )
                     }
                 },
@@ -612,6 +620,11 @@ fun ChatScreen(controller: IrisController) {
         )
     }
 
+    // Settings overlay (full screen; covers the drawer)
+    if (showSettings) {
+        SettingsScreen(controller = controller, onBack = { showSettings = false })
+    }
+
     // New channel dialog
     if (showNewChannel) {
         NameDialog(
@@ -741,7 +754,7 @@ private fun TitlePill(channelName: String, modifier: Modifier = Modifier) {
 
 /** M7: compact 36dp header icon button (smaller than the 48dp default). */
 @Composable
-private fun HeaderIconButton(onClick: () -> Unit, content: @Composable () -> Unit) {
+internal fun HeaderIconButton(onClick: () -> Unit, content: @Composable () -> Unit) {
     Box(
         modifier = Modifier
             .size(36.dp)
@@ -804,7 +817,7 @@ private fun LetterAvatar(name: String, size: Dp, color: Color) {
     }
 }
 
-/** Left drawer: channel list + create / set-default / delete. */
+/** Left drawer: channel list + create / set-default / delete / settings. */
 @Composable
 private fun ChannelDrawer(
     channels: List<ChannelInfo>,
@@ -813,6 +826,7 @@ private fun ChannelDrawer(
     onNewChannel: () -> Unit,
     onSetDefault: (ChannelInfo) -> Unit,
     onDelete: (ChannelInfo) -> Unit,
+    onOpenSettings: () -> Unit,
 ) {
     Column(modifier = Modifier.fillMaxSize().padding(12.dp)) {
         Text(
@@ -858,6 +872,10 @@ private fun ChannelDrawer(
         Button(onClick = onNewChannel, modifier = Modifier.fillMaxWidth()) {
             Text("+ New channel")
         }
+        Spacer(modifier = Modifier.height(4.dp))
+        OutlinedButton(onClick = onOpenSettings, modifier = Modifier.fillMaxWidth()) {
+            Text("⚙ Settings")
+        }
     }
 }
 
@@ -876,6 +894,7 @@ private fun ChannelRail(
     onNewChannel: () -> Unit,
     onSetDefault: (ChannelInfo) -> Unit,
     onDelete: (ChannelInfo) -> Unit,
+    onOpenSettings: () -> Unit,
 ) {
     Column(
         modifier = Modifier
@@ -965,10 +984,14 @@ private fun ChannelRail(
         Button(onClick = onNewChannel, modifier = Modifier.fillMaxWidth()) {
             Text("+ New channel")
         }
+        Spacer(modifier = Modifier.height(4.dp))
+        OutlinedButton(onClick = onOpenSettings, modifier = Modifier.fillMaxWidth()) {
+            Text("⚙ Settings")
+        }
     }
 }
 
-/** M6: optional third pane — session info, channel info, last reply, settings. */
+/** M6: optional third pane — session info, channel info, last reply. */
 @Composable
 private fun InspectorPane(
     controller: IrisController,
@@ -976,8 +999,6 @@ private fun InspectorPane(
     currentChannel: ChannelInfo?,
     threads: List<ChannelInfo>,
     items: List<ChatItem>,
-    toolDetail: ToolDetail,
-    threadsEnabled: Boolean,
 ) {
     val lastAssistant = items.lastOrNull {
         it is MessageItem && it.role == ROLE_ASSISTANT && !it.streaming
@@ -1007,16 +1028,6 @@ private fun InspectorPane(
         Text("Last reply", style = MaterialTheme.typography.titleSmall, modifier = Modifier.padding(bottom = 4.dp))
         InfoRow("Model", lastAssistant?.model ?: "—")
         InfoRow("Tokens", lastAssistant?.tokens?.toString() ?: "—")
-        Spacer(modifier = Modifier.height(8.dp))
-        Text("Settings", style = MaterialTheme.typography.titleSmall, modifier = Modifier.padding(bottom = 4.dp))
-        Row {
-            TextButton(onClick = { controller.cycleToolDetail() }) {
-                Text("tools: ${toolDetail.label}")
-            }
-            TextButton(onClick = { controller.toggleThreads() }) {
-                Text(if (threadsEnabled) "threads: on" else "threads: off")
-            }
-        }
     }
 }
 
@@ -1104,7 +1115,7 @@ private fun TopicSwitcher(
 }
 
 @Composable
-private fun TopicChip(label: String, selected: Boolean, onClick: () -> Unit) {
+internal fun TopicChip(label: String, selected: Boolean, onClick: () -> Unit) {
     Box(
         modifier = Modifier
             .clip(RoundedCornerShape(12.dp))
@@ -1683,7 +1694,7 @@ private fun ToolCard(tool: ToolItem, detail: ToolDetail) {
     }
 }
 
-private val ToolDetail.label: String
+internal val ToolDetail.label: String
     get() = when (this) {
         ToolDetail.EVERYTHING -> "everything"
         ToolDetail.TRUNCATED -> "truncated"

app/shared/src/commonMain/kotlin/iris/ui/screens/SettingsScreen.kt

@@ -0,0 +1,149 @@
+package iris.ui.screens
+
+import androidx.compose.foundation.Canvas
+import androidx.compose.foundation.background
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Switch
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.graphics.Path
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import iris.state.IrisController
+import iris.state.ToolDetail
+import iris.ui.theme.IrisColors
+
+/**
+ * Settings screen (post-M7): app-level preferences, opened from the channel
+ * drawer / rail. More settings land here over time.
+ */
+@Composable
+fun SettingsScreen(controller: IrisController, onBack: () -> Unit) {
+    val threadsEnabled by controller.threadsEnabled.collectAsState()
+    val toolDetail by controller.toolDetail.collectAsState()
+
+    Box(modifier = Modifier.fillMaxSize().background(IrisColors.background)) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .verticalScroll(rememberScrollState())
+                .padding(12.dp),
+        ) {
+            Row(
+                verticalAlignment = Alignment.CenterVertically,
+                modifier = Modifier.padding(bottom = 12.dp),
+            ) {
+                HeaderIconButton(onClick = onBack) {
+                    BackArrow()
+                }
+                Spacer(modifier = Modifier.width(8.dp))
+                Text("Settings", style = MaterialTheme.typography.titleMedium)
+            }
+
+            Text(
+                "Chat",
+                style = MaterialTheme.typography.titleSmall,
+                modifier = Modifier.padding(bottom = 4.dp),
+            )
+            SettingsCard {
+                Row(
+                    verticalAlignment = Alignment.CenterVertically,
+                    modifier = Modifier.fillMaxWidth(),
+                ) {
+                    Column(modifier = Modifier.weight(1f)) {
+                        Text("🧵 Threads", fontSize = 14.sp)
+                        Text(
+                            "Show topics in the chat view",
+                            fontSize = 12.sp,
+                            color = IrisColors.textDim,
+                        )
+                    }
+                    Switch(
+                        checked = threadsEnabled,
+                        onCheckedChange = { controller.toggleThreads() },
+                    )
+                }
+            }
+
+            Text(
+                "Tools",
+                style = MaterialTheme.typography.titleSmall,
+                modifier = Modifier.padding(top = 12.dp, bottom = 4.dp),
+            )
+            SettingsCard {
+                Text("🔧 Tool detail", fontSize = 14.sp)
+                Text(
+                    "How much tool activity to show",
+                    fontSize = 12.sp,
+                    color = IrisColors.textDim,
+                )
+                Spacer(modifier = Modifier.height(8.dp))
+                Row(horizontalArrangement = Arrangement.spacedBy(6.dp)) {
+                    ToolDetail.entries.forEach { d ->
+                        TopicChip(
+                            label = d.label.replaceFirstChar { it.uppercaseChar() },
+                            selected = toolDetail == d,
+                            onClick = { controller.setToolDetail(d) },
+                        )
+                    }
+                }
+            }
+        }
+    }
+}
+
+/** Material-style back arrow (vector, matches the app's icon weight). */
+@Composable
+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()
+        }
+        drawPath(path, color)
+    }
+}
+
+/** Settings row container (panel card). */
+@Composable
+private fun SettingsCard(content: @Composable () -> Unit) {
+    Column(
+        modifier = Modifier
+            .fillMaxWidth()
+            .clip(RoundedCornerShape(12.dp))
+            .background(IrisColors.panel)
+            .padding(12.dp),
+    ) {
+        content()
+    }
+}

app/shared/src/desktopMain/kotlin/iris/platform/DesktopSecureStore.kt

@@ -34,6 +34,8 @@ class DesktopSecureStore : SecureStore {
         val fcmToken: String = "",
         val ntfyTopic: String = "",
         val ntfyServer: String = "",
+        val threadsEnabled: Boolean = false,
+        val toolDetail: String = "truncated",
     )
 
     init {
@@ -133,6 +135,20 @@ class DesktopSecureStore : SecureStore {
             save(d.copy(ntfyServer = value))
         }
 
+    override var threadsEnabled: Boolean
+        get() = load().threadsEnabled
+        set(value) {
+            val d = load()
+            save(d.copy(threadsEnabled = value))
+        }
+
+    override var toolDetail: String
+        get() = load().toolDetail.ifBlank { "truncated" }
+        set(value) {
+            val d = load()
+            save(d.copy(toolDetail = value))
+        }
+
     override fun savePairing(url: String, token: String) {
         val d = load()
         save(d.copy(serverUrl = url.trim()))