feat: Enhance metrics collection and turn tracing for assistant responses

feat: Enhance metrics collection and tracing for assistant text

codex fixex

feat: Enhance voice activity detection and turn tracing features

feat: Add Deepgram STT provider support and enhance configuration options

feat: Add support for Deepgram TTS provider and related configurations

feat: Introduce MCP startup greeting timeout and PocketTTS connection timeout settings

feat: Enhance LiveKit worker configuration and documentation

refactor: Consolidate LLM runtime configuration using LLMSettings

feat: Add support for extra MCP server URLs and enhance assistant instructions

feat: Update LLM and PocketTTS connection options in session management

feat: Introduce turn pipeline summary and enhance tool execution metrics

feat: Add post-tool response timeout and enhance error handling in channel metrics

refactor: Restructure agent components and remove unused files