fix(chat): enable in-place subtask navigation in embedded session-chat iframe (#2138)

packages/ui/src/App.tsx

@@ -54,6 +54,7 @@ import { MCP_OAUTH_CALLBACK_PATH } from '@/components/sections/mcp/mcpOAuth';
 import { lazyWithChunkRecovery } from '@/lib/chunkLoadRecovery';
 import { useI18n } from '@/lib/i18n';
 import { applyMobileKeyboardMode } from '@/lib/mobileKeyboardMode';
+import { isEmbeddedSessionChat } from '@/components/layout/contextPanelEmbeddedChat';
 import { SyncAppEffects } from '@/apps/AppEffects';
 import { resetAppForRuntimeEndpointChange } from '@/apps/runtimeEndpointReset';
 import { useAppFontEffects } from '@/apps/useAppFontEffects';
@@ -117,15 +118,11 @@ const normalizeEmbeddedDirectory = (value: string | null | undefined): string =>
 };
 
 const readEmbeddedSessionChatConfig = (): EmbeddedSessionChatConfig | null => {
-  if (typeof window === 'undefined') {
+  if (typeof window === 'undefined' || !isEmbeddedSessionChat()) {
     return null;
   }
 
   const params = new URLSearchParams(window.location.search);
-  if (params.get('ocPanel') !== 'session-chat') {
-    return null;
-  }
-
   const sessionIdRaw = params.get('sessionId');
   const sessionId = typeof sessionIdRaw === 'string' ? sessionIdRaw.trim() : '';
   if (!sessionId) {
@@ -171,7 +168,12 @@ const EmbeddedSessionChatContent: React.FC<{
     if (expectedDirectory && activeDirectory !== expectedDirectory) return;
 
     const bootstrapKey = `${expectedDirectory}\n${embeddedSessionChat.sessionId}`;
-    if (bootstrapKeyRef.current === bootstrapKey && currentSessionId === embeddedSessionChat.sessionId) {
+    // Skip if this session was already bootstrapped and a session is still
+    // active — allows in-place navigation (e.g. "Open subtask") to change
+    // currentSessionId without this effect forcing it back. Only re-bootstrap
+    // when currentSessionId was cleared (store init, draft, delete/archive,
+    // runtime-switch remount).
+    if (bootstrapKeyRef.current === bootstrapKey && currentSessionId) {
       return;
     }