Fix truthiness check dropping null worktreePath from launch context

When launchContext exists with worktreePath: null, the truthiness check
(launchContext?.worktreePath) incorrectly falls through to the server
thread's worktreePath. This creates an inconsistency where cwd comes
from the launch context but worktreePath comes from the server thread.

Fix by checking for the existence of launchContext itself, so that a
null worktreePath is correctly preserved from the launch context.

Author: cursoragent

apps/web/src/components/ChatView.tsx

@@ -443,7 +443,7 @@ function PersistentThreadTerminalDrawer({
   const [localFocusRequestId, setLocalFocusRequestId] = useState(0);
   const worktreePath = serverThread?.worktreePath ?? draftThread?.worktreePath ?? null;
   const effectiveWorktreePath = useMemo(() => {
-    if (launchContext?.worktreePath) {
+    if (launchContext) {
       return launchContext.worktreePath;
     }
     return worktreePath;