nextcamp - fix new chat from pair and reload

ui/desktop/src/App.tsx

@@ -89,16 +89,32 @@ const PairRouteWrapper = ({
   const setView = useNavigation();
   const routeState =
     (location.state as PairRouteState) || (window.history.state as PairRouteState) || {};
-  const [searchParams] = useSearchParams();
+  const [searchParams, setSearchParams] = useSearchParams();
   const [initialMessage] = useState(routeState.initialMessage);
 
   const resumeSessionId = searchParams.get('resumeSessionId') ?? undefined;
 
+  // Determine which session ID to use:
+  // 1. From route state (when navigating from Hub with a new session)
+  // 2. From URL params (when resuming a session)
+  // 3. From the existing chat state (when navigating to Pair directly)
+  const sessionId = routeState.resumeSessionId || resumeSessionId || chat.sessionId;
+
+  // Update URL with session ID if it's not already there (new chat from pair)
+  useEffect(() => {
+    if (process.env.ALPHA && sessionId && sessionId !== resumeSessionId) {
+      setSearchParams((prev) => {
+        prev.set('resumeSessionId', sessionId);
+        return prev;
+      });
+    }
+  }, [sessionId, resumeSessionId, setSearchParams]);
+
   return process.env.ALPHA ? (
     <Pair2
       setChat={setChat}
       setIsGoosehintsModalOpen={setIsGoosehintsModalOpen}
-      sessionId={routeState.resumeSessionId || resumeSessionId || ''} // TODO(Douwe) one of them should be set now
+      sessionId={sessionId}
       initialMessage={initialMessage}
     />
   ) : (