docs(conductor): Synchronize docs for track 'Codebase Audit and Cleanup'

conductor/tech-stack.md

@@ -22,7 +22,8 @@
 - **DeepSeek (Dedicated SDK):** Integrated for high-performance codegen and reasoning (Phase 2).
 - **Gemini CLI:** Integrated as a headless backend provider, utilizing a custom subprocess adapter and bridge script for tool execution control. Achieves full functional parity with direct SDK usage, including real-time token counting and detailed subprocess observability.
 - **Gemini 3.1 Pro Preview:** Tier 1 Orchestrator model for complex reasoning.
-- **Gemini 2.5 Flash:** High-performance, low-latency model for Tier 2 Tech Lead, Tier 3 Workers, and Tier 4 QA.
+- **Gemini 3-Flash Preview:** High-reasoning low-latency model for Tier 2 Tech Lead.
+- **Gemini 2.5 Flash Lite:** Ultra-low-cost, high-speed model for Tier 3 Workers and Tier 4 QA.
 - **DeepSeek-V3:** Tier 3 Worker model optimized for code implementation.
 - **DeepSeek-R1:** Specialized reasoning model for complex logical chains and "thinking" traces.
 
@@ -40,7 +41,7 @@
 
 - **src/tool_presets.py:** Extends `ToolPresetManager` to handle nested `Tool` models, weights, and global `BiasProfile` persistence within `tool_presets.toml`.
 
-- **src/mcp_client.py (External Extension):** Implements the `ExternalMCPManager` for orchestrating third-party Model Context Protocol servers.
+- **src/mcp_client.py:** Implements the native tool registry and the `ExternalMCPManager` for orchestrating third-party Model Context Protocol servers. Provides dynamic tool discovery and validation.
   - **StdioMCPServer:** Manages local MCP servers via asynchronous subprocess pipes (stdin/stdout/stderr).
   - **RemoteMCPServer (SSE):** Provides a foundation for remote MCP integration via Server-Sent Events.
   - **JSON-RPC 2.0 Engine:** Handles asynchronous message routing, request/response matching, and error handling for all external MCP communication.