feat(m13): cross-resource search + dashboard completion, tests, e2e

- SearchService (cross-resource keyword search across board/chat/todo/file/
  event/meeting/milestone/note with type filter, project isolation)
- DashboardService (project dashboard: in-progress todos, near-due(7d),
  latest chat/board/notes/files(5), next meeting, milestones w/ progress,
  recent activity(10); personal dashboard: my projects, incomplete todos,
  upcoming meetings, unread notifications, overdue tasks, recent activity)
- CalendarRepository.findByProject
- APIs: GET /api/projects/:projectId/search, GET /api/dashboard
- Screens: complete personal dashboard, complete project overview,
  search page + SearchForm, ProjectNav 検索 link
- Unit tests (SearchService, DashboardService) + e2e dashboard

app/api/dashboard/route.ts

@@ -0,0 +1,19 @@
+import { NextResponse } from 'next/server';
+import { getCurrentUser } from '@/lib/auth/getCurrentUser';
+import { createDashboardService } from '@/lib/api/services';
+import { UnauthorizedError } from '@/lib/errors';
+import { handleApiError } from '@/lib/api/handleError';
+
+export const runtime = 'nodejs';
+
+export async function GET() {
+  const user = await getCurrentUser();
+  if (!user) return handleApiError(new UnauthorizedError());
+
+  const service = createDashboardService();
+  try {
+    return NextResponse.json(service.getPersonalDashboard(user.id));
+  } catch (error) {
+    return handleApiError(error);
+  }
+}