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

components/project/SearchForm.tsx

@@ -0,0 +1,72 @@
+'use client';
+
+import { useState, type FormEvent } from 'react';
+import { useRouter } from 'next/navigation';
+
+const TYPES = [
+  { value: '', label: 'すべて' },
+  { value: 'thread', label: '掲示板' },
+  { value: 'chat', label: 'チャット' },
+  { value: 'todo', label: 'ToDo' },
+  { value: 'file', label: 'ファイル' },
+  { value: 'event', label: 'イベント' },
+  { value: 'meeting', label: 'ミーティング' },
+  { value: 'milestone', label: 'マイルストーン' },
+  { value: 'note', label: 'メモ' },
+];
+
+export function SearchForm({
+  projectId,
+  initialQ,
+  initialType,
+}: {
+  projectId: number;
+  initialQ: string;
+  initialType: string;
+}) {
+  const router = useRouter();
+  const [q, setQ] = useState(initialQ);
+  const [type, setType] = useState(initialType);
+
+  function onSubmit(event: FormEvent<HTMLFormElement>) {
+    event.preventDefault();
+    const params = new URLSearchParams();
+    if (q) params.set('q', q);
+    if (type) params.set('type', type);
+    router.push(`/projects/${projectId}/search?${params.toString()}`);
+  }
+
+  return (
+    <form
+      onSubmit={onSubmit}
+      className="flex flex-col gap-2 rounded-lg border bg-white p-4 shadow-sm sm:flex-row"
+      data-testid="search-form"
+    >
+      <input
+        type="text"
+        value={q}
+        onChange={(e) => setQ(e.target.value)}
+        placeholder="キーワード"
+        className="flex-1 rounded border px-3 py-2"
+        data-testid="search-input"
+      />
+      <select
+        value={type}
+        onChange={(e) => setType(e.target.value)}
+        className="rounded border px-2 py-2"
+      >
+        {TYPES.map((t) => (
+          <option key={t.value} value={t.value}>
+            {t.label}
+          </option>
+        ))}
+      </select>
+      <button
+        type="submit"
+        className="rounded bg-blue-600 px-4 py-2 font-medium text-white hover:bg-blue-700"
+      >
+        検索
+      </button>
+    </form>
+  );
+}