feat(roadmap): add posimai-guard milestone with tasks

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

roadmap.json

@@ -323,6 +323,56 @@
       "by": "mai",
       "created": "2026-04-03",
       "tasks": []
+    },
+    {
+      "id": "posimai-guard",
+      "name": "Guard",
+      "description": "AI生成コードのセキュリティスキャナー。Gemini 2.5 Flash による27項目横断解析",
+      "status": "active",
+      "by": "mai",
+      "created": "2026-04-12",
+      "tasks": [
+        {
+          "id": "guard-01",
+          "title": "スキャン履歴（localStorage保存）",
+          "status": "next",
+          "note": "前回結果との比較・再確認ができるように。キー: guard-history[]",
+          "by": "mai",
+          "created": "2026-04-12",
+          "commit": null,
+          "done_at": null
+        },
+        {
+          "id": "guard-02",
+          "title": "結果エクスポート（Markdown / JSON）",
+          "status": "backlog",
+          "note": "Notionやメールでの共有用。危険・注意のみを抽出したサマリー形式",
+          "by": "mai",
+          "created": "2026-04-12",
+          "commit": null,
+          "done_at": null
+        },
+        {
+          "id": "guard-03",
+          "title": "IPベースのレートリミット（5req/min）",
+          "status": "backlog",
+          "note": "Gemini無料枠保護。/api/scan にミドルウェア追加",
+          "by": "mai",
+          "created": "2026-04-12",
+          "commit": null,
+          "done_at": null
+        },
+        {
+          "id": "guard-04",
+          "title": "再スキャンボタン（同ファイルで再実行）",
+          "status": "backlog",
+          "note": "results画面に「同じファイルで再スキャン」ボタンを追加",
+          "by": "mai",
+          "created": "2026-04-12",
+          "commit": null,
+          "done_at": null
+        }
+      ]
     }
   ]
 }