docs(conductor): Synchronize docs for track 'RAG Support'

conductor/tech-stack.md

@@ -40,12 +40,14 @@
 - **src/tool_bias.py:** Implements the `ToolBiasEngine` for semantic tool description nudging and dynamic tooling strategy generation.
 
 - **src/tool_presets.py:** Extends `ToolPresetManager` to handle nested `Tool` models, weights, and global `BiasProfile` persistence within `tool_presets.toml`.
-
 - **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.
 
+- **src/rag_engine.py:** Core RAG implementation managing the vector store lifecycle, chunking strategies (character-based and AST-aware), and multi-provider search. Integrates with **ChromaDB** for local persistence and provides a bridge for external MCP retrieval tools.
+
+- **src/paths.py:** Centralized module for path resolution.
 - **tree-sitter / AST Parsing:** For deterministic AST parsing and automated generation of curated "Skeleton Views" and "Targeted Views" (extracting specific functions and their dependencies). Features an integrated AST cache with mtime-based invalidation to minimize re-parsing overhead. Supplemented by `SummaryCache` which provides persistent, hash-based (SHA256) caching with LRU eviction for AI-generated file summaries.
 - **pydantic / dataclasses:** For defining strict state schemas (Tracks, Tickets) used in linear orchestration.
 - **tomli-w:** For writing TOML configuration files.