HTML artifacts: render agent-sent HTML/CSS/JS code blocks in an in-app WebView (Android platform WebView, desktop JCEF/KCEF) via a full-screen preview; artifact card with Preview button + code toggle, shown only once the message stops streaming; webview-multiplatform 1.9.40 + KCEF deps, detection + unit tests

app/shared/src/commonMain/kotlin/iris/IrisApp.kt

@@ -17,6 +17,7 @@ import iris.data.SecureStore
 import iris.net.GatewayClient
 import iris.platform.setActiveController
 import iris.state.IrisController
+import iris.ui.ArtifactPreviewOverlay
 import iris.ui.screens.ChatScreen
 import iris.ui.screens.ConnectScreen
 import iris.ui.theme.IrisColors
@@ -96,6 +97,9 @@ fun IrisApp(
                         // without blocking the view (M7's full-screen spinner is gone).
                         else -> ChatScreen(controller)
                     }
+                    // M9: full-screen HTML artifact preview (opened from an
+                    // artifact card in the chat); covers everything while open.
+                    ArtifactPreviewOverlay()
                 }
             }
         }