feat(groups): chat_group 补 6 群主/建群列 + 复合PK迁移修复 + 存量回填

对齐云客员工聊天窗口·微信群 tab(2026-08-25 真机验证 raw_json 键):
- ChatGroup 加列 owner_name/owner_wxid/owner_alias/owner_avatar/
  friend_count/create_time(全 nullable)
- scraper _normalize_chat_group 同名提取;createTime 兼容 ms-int 与
  'YYYY-MM-DD HH:mm:ss'(smoke.db 实测 1105 行全为后者),复用
  _parse_add_time 归一 ms-epoch
- 迁移 099ac2097fa2:加 6 列 + 修复 Task1 评审遗留 drift——PK 由单列
  room_id 变更为复合 (room_id, channel, owner_account_id) 且
  owner_account_id NOT NULL(对齐模型 8a99940;smoke.db 1105 行无 NULL,
  未兜底编造数据);SQLite 走 batch 重建(copy_from 显式旧结构),
  MySQL 渲染为直接 ALTER(离线 --sql 已验证)
- 回填脚本 scripts/backfill_chat_group_fields.py(幂等,逐列只补空);
  smoke.db 实跑 backfilled 1105/1105,重跑 0/1105
- GroupOut 加 6 字段(model_validate 自动输出,路由无改)

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

yunke-server/app/db/models.py

@@ -290,6 +290,16 @@ class ChatGroup(Base):
     last_chat_time: Mapped[int | None] = mapped_column(BigInteger, nullable=True)
     update_time: Mapped[int | None] = mapped_column(BigInteger, nullable=True)
 
+    # 通讯录·微信群 tab 对齐云客的补充列（2026-08-25，从 raw_json 提取：
+    # ownerName/ownerWchatId/ownerAlias/ownerImage/friendCount/createTime；
+    # createTime 兼容 ms-int 与 'YYYY-MM-DD HH:mm:SS' 两种上游形态，归一为 ms）
+    owner_name: Mapped[str | None] = mapped_column(String(255), nullable=True)  # 群主昵称(上游脱敏)
+    owner_wxid: Mapped[str | None] = mapped_column(String(128), nullable=True)
+    owner_alias: Mapped[str | None] = mapped_column(String(255), nullable=True)  # 群主微信号
+    owner_avatar: Mapped[str | None] = mapped_column(String(1024), nullable=True)
+    friend_count: Mapped[int | None] = mapped_column(Integer, nullable=True)  # 群成员中员工好友数
+    create_time: Mapped[int | None] = mapped_column(BigInteger, nullable=True)  # 建群时间 ms epoch
+
     version: Mapped[str | None] = mapped_column(String(64), nullable=True)
     raw_json: Mapped[dict[str, Any] | None] = mapped_column(JSON, nullable=True)
     fetched_at: Mapped[dt.datetime] = _fetched_at()