refactor(architecture): 修复模块依赖违规并强化架构守护

- 字幕编排上移 DownloadChain.download_site_subtitles，SubtitleModule 仅保留站点链接解析
- TransferChain.recommend_name 上移 TV episodes_info 获取，filemanager 模块不再导入 TmdbChain
- endpoint 穿透修复：WXBizMsgCrypt3 迁至 adapters/external/wechat_crypt.py；
  music/tmdb 缓存管理、listenbrainz 常量、TMDbException、WechatClawBot 辅助统一经 chain 包装
- RuleParser 与 builtin_rules 合并为 application/filter_rules.py；
  fsproxy/fsworker 迁至 adapters/system/
- chain/__init__.py 删除 qbittorrentapi/transmission_rpc 导入，消除后端协议类型泄漏
- 架构守护测试新增三项检查：模块间隔离、入口层穿透、下载器 SDK 泄漏
- 文档同步：05-architecture.md 记录 DB/Oper 聚合例外与迁移文件位置，AGENTS.md 更新所有权表

tests/test_download_chain.py

@@ -148,6 +148,7 @@ def test_download_single_submits_download_added_to_background(monkeypatch):
     chain = DownloadChain.__new__(DownloadChain)
     chain.download = MagicMock(return_value=("qb", "hash123", "Original", "添加下载成功"))
     chain.download_added = MagicMock()
+    chain.download_site_subtitles = MagicMock()
     chain.eventmanager = MagicMock()
     chain.eventmanager.send_event.return_value = None
     chain.post_message = MagicMock()
@@ -191,6 +192,11 @@ def test_download_single_submits_download_added_to_background(monkeypatch):
         download_dir=Path("/downloads"),
         torrent_content=b"torrent-content",
     )
+    chain.download_site_subtitles.assert_called_once_with(
+        context=context,
+        download_dir=Path("/downloads"),
+        torrent_content=b"torrent-content",
+    )
 
 
 def test_download_single_supplements_category_before_download_event(monkeypatch):
@@ -268,6 +274,7 @@ def test_download_single_persists_custom_words_snapshot(monkeypatch):
     chain = DownloadChain.__new__(DownloadChain)
     chain.download = MagicMock(return_value=("qb", "hash123", "Original", "添加下载成功"))
     chain.download_added = MagicMock()
+    chain.download_site_subtitles = MagicMock()
     chain.eventmanager = MagicMock()
     chain.eventmanager.send_event.return_value = None
     chain.post_message = MagicMock()