feat: Add extract_topic and voice_chat tools to MCP service, enhancing functionality for topic extraction and chatbot responses. Update models and routes to support new features.

refactor: Remove GenerateArgumentRequest and GenerateArgumentResponse models; update generate_argument endpoint to accept topic and position parameters.

Refactor MCP tool handling to use hardcoded tool definitions and improve return value handling in health check and tool calls

Update mcp_service.py

update mcp part

correct main

Update mcp_service.py

Update mcp_service.py

update mcp part

add mcp part