chore(deps): 升级 paddleocr 与 transformers，新增 pytest-asyncio

Refactor video audio extractor plugin and enhance functionality

feat: 新增内置 MCP 和内容处理插件

chore(docs): 更新 README 以支持 React SPA 和 uv 管理

chore: cleanup deprecated files and update documentation

test(mcp): add unit tests for decorators and plugin_registry

refactor(mcp): migrate from FastMCP v1 to MCPServer v2, remove legacy tools

refactor(mcp): 重构MCP服务为无状态模式并规范工具定义