feat(sns): 增加朋友圈时间线与图片本地缓存接口

- 新增 /api/sns/timeline：优先走 WCDB realtime 读取 sns.db，支持分页/用户过滤/关键字

- 新增 /api/sns/media：本地缓存（cache/.../Sns/Img）解密优先，支持手动 pick/避开重复

- 新增 /api/sns/media_candidates 与 /api/sns/media_picks：候选 key 列表与本机持久化匹配表

- wcdb_realtime 增加 exec_query/get_sns_timeline 封装，并在连接时 set_my_wxid 上下文

- 更新 wcdb_api.dll 并补齐 MSVC runtime 依赖

src/wechat_decrypt_tool/api.py

@@ -18,6 +18,7 @@ from .routers.decrypt import router as _decrypt_router
 from .routers.health import router as _health_router
 from .routers.keys import router as _keys_router
 from .routers.media import router as _media_router
+from .routers.sns import router as _sns_router
 from .routers.wechat_detection import router as _wechat_detection_router
 from .wcdb_realtime import WCDB_REALTIME, shutdown as _wcdb_shutdown
 
@@ -51,6 +52,7 @@ app.include_router(_media_router)
 app.include_router(_chat_router)
 app.include_router(_chat_export_router)
 app.include_router(_chat_media_router)
+app.include_router(_sns_router)
 
 
 class _SPAStaticFiles(StaticFiles):