feat(KB-618): add multi-project support to dashboard

- Add project API methods and types (fetchProjects, registerProject, fetchProjectHealth, etc.)
- Add ProjectCard component with health metrics, status badges, and pause/resume actions
- Add server-side project management routes for multi-project orchestration
- Add ActivityFeed component with grouped entries and project badges
- Add SetupWizard component with 5-step project creation flow
- Fix TypeScript errors in server routes for listProjects and getGlobalConcurrencyState

packages/dashboard/app/hooks/useTasks.ts

@@ -30,41 +30,11 @@ export function useTasks() {
   const tasksRef = useRef(tasks);
   tasksRef.current = tasks;
 
-  // Ref to track last visibility fetch time for debouncing (1 second minimum)
-  const lastVisibilityFetchRef = useRef<number>(0);
-  const VISIBILITY_FETCH_DEBOUNCE_MS = 1000;
-
   // Fetch initial tasks
   useEffect(() => {
     api.fetchTasks().then((tasks) => setTasks(tasks.map(normalizeTask))).catch(() => setTasks([]));
   }, []);
 
-  // Visibility change listener - refresh tasks when tab becomes visible
-  useEffect(() => {
-    const handleVisibilityChange = () => {
-      if (document.visibilityState === "visible") {
-        const now = Date.now();
-        const timeSinceLastFetch = now - lastVisibilityFetchRef.current;
-
-        // Debounce: only fetch if at least 1 second has passed since last visibility fetch
-        if (timeSinceLastFetch >= VISIBILITY_FETCH_DEBOUNCE_MS) {
-          lastVisibilityFetchRef.current = now;
-          api.fetchTasks()
-            .then((tasks) => setTasks(tasks.map(normalizeTask)))
-            .catch(() => {
-              // Silently ignore fetch errors on visibility change
-            });
-        }
-      }
-    };
-
-    document.addEventListener("visibilitychange", handleVisibilityChange);
-
-    return () => {
-      document.removeEventListener("visibilitychange", handleVisibilityChange);
-    };
-  }, []);
-
   // SSE live updates
   useEffect(() => {
     let closedByCleanup = false;