Adds a search_messages tool that hits the Django FTS5/semantic/hybrid
endpoint for keyword-quality text search over message bodies, and an
LLM-based reranker inside tool_search_rag (gated by SEARCH_RAG_RERANK,
default on). Reranker pulls ~3x candidates from the vector index, asks
the chat model to rank by relevance, and falls back to vector order on
parse failure.
The reranker shares the active chat turn's OllamaClient so num_ctx and
sampling match — otherwise Ollama unloads/reloads the model on every
rerank call. (Unverified end-to-end; caught by inspection, awaiting
e2e confirmation.)
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
e4a3536f87