feat(m7): markdown notes with CRUD, preview, search, tests, e2e

- ProjectNoteRepository (CRUD, soft-delete, search title/body/tags,
  pinned-first ordering, index usage) + NoteService (membership permission,
  author/admin edit/delete, note_updated notification to other members,
  note_created/note_updated activity logs, pin/tags)
- APIs: notes list/create/detail/edit/delete
- Screens: notes list + NoteForm, note detail + NoteEditor + MarkdownBody
  preview, ProjectNav メモ link
- Unit tests (ProjectNoteRepository, NoteService) + e2e markdown-notes.spec

components/notes/NoteEditor.tsx

@@ -0,0 +1,102 @@
+'use client';
+
+import { useState, type FormEvent } from 'react';
+import { useRouter } from 'next/navigation';
+import type { ProjectNote } from '@/lib/types';
+
+export function NoteEditor({
+  projectId,
+  note,
+}: {
+  projectId: number;
+  note: ProjectNote;
+}) {
+  const router = useRouter();
+  const [title, setTitle] = useState(note.title);
+  const [bodyMd, setBodyMd] = useState(note.bodyMd);
+  const [tags, setTags] = useState(note.tags ?? '');
+  const [isPinned, setIsPinned] = useState(note.isPinned === 1);
+  const [error, setError] = useState<string | null>(null);
+  const [saved, setSaved] = useState(false);
+  const [loading, setLoading] = useState(false);
+
+  async function onSubmit(event: FormEvent<HTMLFormElement>) {
+    event.preventDefault();
+    setLoading(true);
+    setError(null);
+    setSaved(false);
+    const res = await fetch(`/api/projects/${projectId}/notes/${note.id}`, {
+      method: 'PATCH',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        title,
+        bodyMd,
+        tags: tags || null,
+        isPinned: isPinned ? 1 : 0,
+      }),
+    });
+    setLoading(false);
+    if (res.ok) {
+      setSaved(true);
+      router.refresh();
+    } else {
+      const b = (await res.json().catch(() => null)) as {
+        error?: { message?: string };
+      } | null;
+      setError(b?.error?.message ?? '更新に失敗しました');
+    }
+  }
+
+  return (
+    <form
+      onSubmit={onSubmit}
+      className="space-y-3 rounded-lg border bg-white p-4 shadow-sm"
+    >
+      <h2 className="text-sm font-semibold text-gray-700">編集</h2>
+      <input
+        type="text"
+        value={title}
+        onChange={(e) => setTitle(e.target.value)}
+        className="w-full rounded border px-3 py-2"
+        required
+        maxLength={200}
+      />
+      <textarea
+        value={bodyMd}
+        onChange={(e) => setBodyMd(e.target.value)}
+        className="min-h-[160px] w-full rounded border px-3 py-2"
+        required
+      />
+      <div className="flex gap-2">
+        <input
+          type="text"
+          placeholder="タグ（カンマ区切り）"
+          value={tags}
+          onChange={(e) => setTags(e.target.value)}
+          className="flex-1 rounded border px-3 py-2"
+        />
+        <label className="flex items-center gap-1 text-sm">
+          <input
+            type="checkbox"
+            checked={isPinned}
+            onChange={(e) => setIsPinned(e.target.checked)}
+          />
+          ピン留め
+        </label>
+      </div>
+      {error && (
+        <p className="text-sm text-red-600" role="alert">
+          {error}
+        </p>
+      )}
+      {saved && <p className="text-sm text-green-600">メモを更新しました</p>}
+      <button
+        type="submit"
+        disabled={loading}
+        className="rounded bg-blue-600 px-4 py-2 font-medium text-white hover:bg-blue-700 disabled:opacity-50"
+      >
+        {loading ? '保存中...' : '保存'}
+      </button>
+    </form>
+  );
+}