fix(desktop): validate persisted tab slugs against current workspace list

Desktop tabs persist their full path to localStorage (multica_tabs), so
a tab path like /naiyuan/issues survives app restarts, account switches,
and workspace deletions. Any stale slug caused WorkspaceRouteLayout to
render NoAccessPage immediately on login — the user saw "Workspace not
available" every time they opened the app, with no way to recover
except manually opening a new tab or clearing localStorage.

Root cause: persisted URL strings outlive the server-state they
reference. The auth initializer fetches a fresh workspace list on every
startup, but nothing validated the tab paths against it.

Fix: add tab-store.validateWorkspaceSlugs(validSlugs). Runs on every
change to the workspace list query data (login, background refetch,
realtime workspace:deleted). Any tab whose first path segment isn't in
the valid slug set is reset to `/`, where IndexRedirect picks a live
workspace (or /new-workspace if the user has none). Idempotent, so
over-triggering is safe. Tabs on global paths (/login, /new-workspace,
/invite/...) are left alone.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/desktop/src/renderer/src/App.tsx

@@ -10,6 +10,7 @@ import { Toaster } from "sonner";
 import { DesktopLoginPage } from "./pages/login";
 import { DesktopShell } from "./components/desktop-layout";
 import { UpdateNotification } from "./components/update-notification";
+import { useTabStore } from "./stores/tab-store";
 
 function AppContent() {
   const user = useAuthStore((s) => s.user);
@@ -81,6 +82,19 @@ function AppContent() {
     enabled: !!user,
   });
   const wsCount = workspaces?.length ?? 0;
+
+  // Validate persisted tab paths against the current user's workspace list.
+  // Tabs survive across app restarts and account switches (persisted to
+  // localStorage `multica_tabs`), so a tab path like `/naiyuan/issues` may
+  // reference a workspace the current user can't access — showing
+  // NoAccessPage every time they open the app. Reset any such tab to `/`
+  // so IndexRedirect picks a valid workspace. Runs on every workspace list
+  // change (login, refetch, realtime workspace:deleted); idempotent.
+  useEffect(() => {
+    if (!workspaces) return;
+    const validSlugs = new Set(workspaces.map((w) => w.slug));
+    useTabStore.getState().validateWorkspaceSlugs(validSlugs);
+  }, [workspaces]);
   // null = undecided (pre-login or list hasn't settled yet)
   // true  = session started with zero workspaces; next transition to >=1 triggers restart
   // false = session started with >=1 workspace, OR we've already restarted; skip

apps/desktop/src/renderer/src/stores/tab-store.ts

@@ -39,6 +39,15 @@ interface TabStore {
   updateTabHistory: (tabId: string, historyIndex: number, historyLength: number) => void;
   /** Reorder tabs by moving one from fromIndex to toIndex. Preserves router/history. */
   moveTab: (fromIndex: number, toIndex: number) => void;
+  /**
+   * Reset any tab whose first path segment references a workspace slug the
+   * current user doesn't have access to. Called after login + workspace list
+   * is populated (and on every subsequent list change, e.g. realtime
+   * workspace:deleted). Stale tabs get reset to `/` so IndexRedirect picks
+   * a valid workspace; tabs on global paths (/login, /new-workspace, etc.)
+   * are untouched.
+   */
+  validateWorkspaceSlugs: (validSlugs: Set<string>) => void;
 }
 
 // ---------------------------------------------------------------------------
@@ -182,6 +191,36 @@ export const useTabStore = create<TabStore>()(
     if (fromIndex === toIndex) return;
     set((s) => ({ tabs: arrayMove(s.tabs, fromIndex, toIndex) }));
   },
+
+  validateWorkspaceSlugs(validSlugs) {
+    const { tabs } = get();
+    let changed = false;
+    const nextTabs = tabs.map((t) => {
+      // Skip tabs on non-workspace-scoped paths — nothing to validate.
+      if (t.path === "/" || isGlobalPath(t.path)) return t;
+
+      const firstSegment = t.path.split("/").filter(Boolean)[0] ?? "";
+      if (validSlugs.has(firstSegment)) return t;
+
+      // Stale slug: dispose the old router and replace with a fresh one
+      // pointing at `/`. IndexRedirect will send the tab to a valid
+      // workspace (or /new-workspace if the user now has none).
+      changed = true;
+      t.router.dispose();
+      return {
+        ...t,
+        path: DEFAULT_PATH,
+        title: "Issues",
+        icon: resolveRouteIcon(DEFAULT_PATH),
+        router: createTabRouter(DEFAULT_PATH),
+        historyIndex: 0,
+        historyLength: 1,
+      };
+    });
+
+    if (!changed) return;
+    set({ tabs: nextTabs });
+  },
     }),
     {
       name: "multica_tabs",