feat(deploy): MySQL容器实测打通(3个方言bug修复)+部署文档

- repos: on_duplicate只更新实际插入列(fetched_at等Python-default列,
  SQLite excluded容忍/MySQL new.*直接报Unknown column)
- repos: _coerce_int增加日期字符串→ms epoch分支 + _INT_FIELDS补
  last_update/last_chat_time/timestamp/update_time(字符串直通BigInteger)
- models: wechat_account.db_size Integer→BigInteger(实测2.17GB超32位上限)
- compose: mysql不映射宿主机3306(本机已占;容器内服务名互联)
- docs/DEPLOY.md: 服务器部署全指南(架构/步骤/数据迁移/运维命令/注意事项)
- 容器实测:Playwright抓取55账号→MySQL upsert全通

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

docker-compose.yml

@@ -43,10 +43,9 @@ services:
       retries: 10
     volumes:
       - mysql_data:/var/lib/mysql
-    ports:
-      # Expose for host-side inspection (mysql CLI / DBeaver); omit if you
-      # don't need cross-container access from the host.
-      - "3306:3306"
+    # 3306 不映射宿主机:容器内通过服务名 mysql:3306 互联;宿主机检查用
+    # docker compose exec mysql mysql -uyunke -p(2026-08-21 本机 3306 已被
+    # 本地 MySQL 占用,发布环境也无需对外暴露数据库)
 
   redis:
     image: redis:7-alpine