Implement Lesson Practice 2 Agent with state management and routing logic; add practice and teaching agent functions; create prompts for conversation and teaching; establish pronunciation API with lesson data and search functionality.

feat: evaluation when end

feat: text to speech for AI response

prompt: optimize

feat: audio v2 multi agent

remove conversation management

Add trim_history function and update lesson chat route to handle text and audio inputs

Add lesson management functionality with JSON data integration and response models

Implement lesson practice agent and related functionality