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.

feat: Enhance ToolCallRequest and ToolCallResponse models with detailed examples and descriptions for improved clarity and usability in MCP tool calls.

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

Add response models for new MCP tools: DetectStance, MatchKeypoint, TranscribeAudio, GenerateSpeech, and GenerateArgument

add mcp part