Fix sandbox origin isolation and Android build issues

android/app/src/main/java/pub/ditto/app/SandboxPlugin.java

@@ -13,7 +13,7 @@ import android.webkit.WebResourceResponse;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
-import android.widget.FrameLayout;
+import androidx.coordinatorlayout.widget.CoordinatorLayout;
 
 import com.getcapacitor.JSObject;
 import com.getcapacitor.Plugin;
@@ -80,9 +80,11 @@ public class SandboxPlugin extends Plugin {
             sandboxes.put(sandboxId, sandbox);
 
             // Add the WebView on top of the Capacitor WebView.
+            // The parent is a CoordinatorLayout — using the wrong LayoutParams
+            // type causes a ClassCastException when it intercepts touch events.
             View capWebView = getBridge().getWebView();
             ViewGroup parent = (ViewGroup) capWebView.getParent();
-            FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(pxWidth, pxHeight);
+            CoordinatorLayout.LayoutParams params = new CoordinatorLayout.LayoutParams(pxWidth, pxHeight);
             params.leftMargin = pxX;
             params.topMargin = pxY;
             parent.addView(sandbox.webView, params);
@@ -126,7 +128,7 @@ public class SandboxPlugin extends Plugin {
                 return;
             }
 
-            FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(pxWidth, pxHeight);
+            CoordinatorLayout.LayoutParams params = new CoordinatorLayout.LayoutParams(pxWidth, pxHeight);
             params.leftMargin = pxX;
             params.topMargin = pxY;
             sandbox.webView.setLayoutParams(params);
@@ -385,7 +387,7 @@ public class SandboxPlugin extends Plugin {
                     "  onMessage: function(data) {" +
                     "    var event = {" +
                     "      data: data," +
-                    "      origin: 'sandbox://app'," +
+                    "      origin: 'https://" + sandbox.id + ".sandbox.native'," +
                     "      source: window.parent," +
                     "      type: 'message'" +
                     "    };" +

ios/App/App/SandboxPlugin.swift

@@ -194,10 +194,9 @@ private class SandboxInstance: NSObject, WKScriptMessageHandler {
         self.id = id
         self.plugin = plugin
 
-        // Use a shortened ID for the scheme (URL schemes have length limits
-        // and must start with a letter). We use "sbx-" prefix + first 12 chars.
-        let schemeId = String(id.prefix(12))
-        self.customScheme = "sbx-\(schemeId)"
+        // Each sandbox gets a unique custom URL scheme so that WKWebView
+        // assigns a distinct origin, isolating localStorage/IndexedDB/cookies.
+        self.customScheme = "sbx-\(id)"
 
         self.schemeHandler = SandboxSchemeHandler(
             sandboxId: id,

src/components/SandboxFrame.tsx

@@ -413,7 +413,34 @@ const SandboxFrameNative = forwardRef<SandboxFrameHandle, SandboxFrameProps>(
 
         const rect = el.getBoundingClientRect();
 
-        // Create the native WebView.
+        // Register listeners BEFORE creating the WebView. On Android,
+        // `shouldInterceptRequest` fires on a background thread as soon
+        // as the WebView starts loading — if the fetch listener isn't
+        // registered yet, the event is lost and the request times out
+        // (the thread blocks via CountDownLatch waiting for a response
+        // that never arrives).
+        const fetchListener = await SandboxPlugin.addListener(
+          'fetch',
+          (event: SandboxFetchEvent) => {
+            if (event.id !== id) return;
+            handleNativeFetch(event);
+          },
+        );
+        listeners.push(fetchListener);
+
+        const scriptListener = await SandboxPlugin.addListener(
+          'scriptMessage',
+          (event: SandboxScriptMessageEvent) => {
+            if (event.id !== id) return;
+            handleNativeScriptMessage(event);
+          },
+        );
+        listeners.push(scriptListener);
+
+        if (cancelled || destroyedRef.current) return;
+
+        // Create the native WebView. Fetch events from the initial load
+        // will be handled by the listeners registered above.
         await SandboxPlugin.create({
           id,
           frame: {
@@ -431,26 +458,6 @@ const SandboxFrameNative = forwardRef<SandboxFrameHandle, SandboxFrameProps>(
         }
 
         createdRef.current = true;
-
-        // Listen for fetch requests from the native URL scheme handler.
-        const fetchListener = await SandboxPlugin.addListener(
-          'fetch',
-          (event: SandboxFetchEvent) => {
-            if (event.id !== id) return;
-            handleNativeFetch(event);
-          },
-        );
-        listeners.push(fetchListener);
-
-        // Listen for script messages (custom JSON-RPC from injected scripts).
-        const scriptListener = await SandboxPlugin.addListener(
-          'scriptMessage',
-          (event: SandboxScriptMessageEvent) => {
-            if (event.id !== id) return;
-            handleNativeScriptMessage(event);
-          },
-        );
-        listeners.push(scriptListener);
       }
 
       // ---------------------------------------------------------------