feat(FN-3800): add session switcher to chat header and mobile switcher

This merge delivers five features: a session switcher for the chat header with mobile-aware dropdown styling and proper ARIA state, mailbox notification events with deep-link highlighting to the unread task, a fix for org chart connector endpoints in wide subtrees, a correction to merge finalize so

Fusion-Task-Id: FN-3800

packages/dashboard/app/hooks/useViewState.ts

@@ -125,6 +125,17 @@ export function useViewState(options: UseViewStateOptions): UseViewStateResult {
     setScopedItem("kb-dashboard-task-view", taskView, currentProject?.id);
   }, [currentProject?.id, taskView]);
 
+  useEffect(() => {
+    if (typeof window === "undefined") {
+      return;
+    }
+
+    const viewParam = new URLSearchParams(window.location.search).get("view");
+    if (viewParam && isTaskView(viewParam)) {
+      setTaskView(normalizeTaskView(viewParam));
+    }
+  }, []);
+
   useEffect(() => {
     if (projectsLoading || currentProjectLoading) return;