feat(canvas): remove setMode; host A2UI in scaffold

apps/android/app/src/main/java/com/steipete/clawdis/node/NodeRuntime.kt

@@ -272,7 +272,6 @@ class NodeRuntime(context: Context) {
         buildList {
           add(ClawdisCanvasCommand.Show.rawValue)
           add(ClawdisCanvasCommand.Hide.rawValue)
-          add(ClawdisCanvasCommand.SetMode.rawValue)
           add(ClawdisCanvasCommand.Navigate.rawValue)
           add(ClawdisCanvasCommand.Eval.rawValue)
           add(ClawdisCanvasCommand.Snapshot.rawValue)
@@ -544,14 +543,9 @@ class NodeRuntime(context: Context) {
     return when (command) {
       ClawdisCanvasCommand.Show.rawValue -> BridgeSession.InvokeResult.ok(null)
       ClawdisCanvasCommand.Hide.rawValue -> BridgeSession.InvokeResult.ok(null)
-      ClawdisCanvasCommand.SetMode.rawValue -> {
-        val mode = CanvasController.parseMode(paramsJson)
-        canvas.setMode(mode)
-        BridgeSession.InvokeResult.ok(null)
-      }
       ClawdisCanvasCommand.Navigate.rawValue -> {
         val url = CanvasController.parseNavigateUrl(paramsJson)
-        if (url != null) canvas.navigate(url)
+        canvas.navigate(url)
         BridgeSession.InvokeResult.ok(null)
       }
       ClawdisCanvasCommand.Eval.rawValue -> {
@@ -638,7 +632,8 @@ class NodeRuntime(context: Context) {
       // ignore
     }
 
-    canvas.navigate(a2uiIndexUrl)
+    // Ensure the default canvas scaffold is loaded; A2UI is now hosted there.
+    canvas.navigate("")
     repeat(50) {
       try {
         val ready = canvas.eval(a2uiReadyCheckJS)
@@ -713,8 +708,6 @@ class NodeRuntime(context: Context) {
 
 private data class Quad<A, B, C, D>(val first: A, val second: B, val third: C, val fourth: D)
 
-private const val a2uiIndexUrl: String = "file:///android_asset/CanvasA2UI/index.html"
-
 private const val a2uiReadyCheckJS: String =
   """
   (() => {

apps/android/app/src/main/java/com/steipete/clawdis/node/node/CanvasController.kt

@@ -14,11 +14,8 @@ import android.util.Base64
 import kotlin.coroutines.resume
 
 class CanvasController {
-  enum class Mode { CANVAS, WEB }
-
   @Volatile private var webView: WebView? = null
-  @Volatile private var mode: Mode = Mode.CANVAS
-  @Volatile private var url: String = ""
+  @Volatile private var url: String? = null
 
   private val scaffoldAssetUrl = "file:///android_asset/CanvasScaffold/scaffold.html"
 
@@ -27,17 +24,9 @@ class CanvasController {
     reload()
   }
 
-  fun setMode(mode: Mode) {
-    this.mode = mode
-    reload()
-  }
-
   fun navigate(url: String) {
-    this.url = url
-    if (url.trim().isNotBlank()) {
-      // `canvas.navigate` is expected to show web content; default to WEB mode to match iOS.
-      this.mode = Mode.WEB
-    }
+    val trimmed = url.trim()
+    this.url = if (trimmed.isBlank() || trimmed == "/") null else trimmed
     reload()
   }
 
@@ -51,17 +40,12 @@ class CanvasController {
   }
 
   private fun reload() {
-    val currentMode = mode
     val currentUrl = url
     withWebViewOnMain { wv ->
-      when (currentMode) {
-        Mode.WEB -> {
-          // Match iOS behavior: if URL is missing/invalid, keep the current page (canvas scaffold).
-          val trimmed = currentUrl.trim()
-          if (trimmed.isBlank()) return@withWebViewOnMain
-          wv.loadUrl(trimmed)
-        }
-        Mode.CANVAS -> wv.loadUrl(scaffoldAssetUrl)
+      if (currentUrl == null) {
+        wv.loadUrl(scaffoldAssetUrl)
+      } else {
+        wv.loadUrl(currentUrl)
       }
     }
   }
@@ -106,19 +90,9 @@ class CanvasController {
     }
 
   companion object {
-    fun parseMode(paramsJson: String?): Mode {
-      val obj = parseParamsObject(paramsJson) ?: return Mode.CANVAS
-      return if (obj.optString("mode", "").equals("web", ignoreCase = true)) {
-        Mode.WEB
-      } else {
-        Mode.CANVAS
-      }
-    }
-
-    fun parseNavigateUrl(paramsJson: String?): String? {
-      val obj = parseParamsObject(paramsJson) ?: return null
-      val url = obj.optString("url", "").trim()
-      return url.takeIf { it.isNotBlank() }
+    fun parseNavigateUrl(paramsJson: String?): String {
+      val obj = parseParamsObject(paramsJson)
+      return obj?.optString("url", "")?.trim().orEmpty()
     }
 
     fun parseEvalJs(paramsJson: String?): String? {

apps/android/app/src/main/java/com/steipete/clawdis/node/protocol/ClawdisProtocolConstants.kt

@@ -9,7 +9,6 @@ enum class ClawdisCapability(val rawValue: String) {
 enum class ClawdisCanvasCommand(val rawValue: String) {
   Show("canvas.show"),
   Hide("canvas.hide"),
-  SetMode("canvas.setMode"),
   Navigate("canvas.navigate"),
   Eval("canvas.eval"),
   Snapshot("canvas.snapshot"),

apps/android/app/src/test/java/com/steipete/clawdis/node/protocol/ClawdisProtocolConstantsTest.kt

@@ -8,7 +8,6 @@ class ClawdisProtocolConstantsTest {
   fun canvasCommandsUseStableStrings() {
     assertEquals("canvas.show", ClawdisCanvasCommand.Show.rawValue)
     assertEquals("canvas.hide", ClawdisCanvasCommand.Hide.rawValue)
-    assertEquals("canvas.setMode", ClawdisCanvasCommand.SetMode.rawValue)
     assertEquals("canvas.navigate", ClawdisCanvasCommand.Navigate.rawValue)
     assertEquals("canvas.eval", ClawdisCanvasCommand.Eval.rawValue)
     assertEquals("canvas.snapshot", ClawdisCanvasCommand.Snapshot.rawValue)