test(dashboard): mock useToast in PlanningModeModal.ui-interactions

These tests render PlanningModeModal bare; it calls useToast() which throws
without a ToastProvider. Mirror the mock already in PlanningModeModal.autosize.
test.tsx. (Pre-existing failure on main; the test is excluded from the CI
quality shards but fails under `--project dashboard-app`/`test:app`.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/dashboard/app/components/__tests__/PlanningModeModal.ui-interactions.test.tsx

@@ -1,5 +1,15 @@
 import { describe, it, expect, vi, beforeEach } from "vitest";
 
+// PlanningModeModal calls useToast(), which throws without a ToastProvider.
+// These tests render it bare, so mock the hook (mirrors PlanningModeModal.autosize.test.tsx).
+vi.mock("../../hooks/useToast", () => ({
+  useToast: () => ({
+    addToast: vi.fn(),
+    removeToast: vi.fn(),
+    toasts: [],
+  }),
+}));
+
 vi.mock("../../hooks/useNavigationHistory", async (importOriginal) => {
   const actual = await importOriginal<typeof import("../../hooks/useNavigationHistory")>();
   return {