Add semantic search over past conversations alongside existing memory facts.
New conversation_chunks table stores user-assistant exchanges with LLM-generated
summaries embedded for retrieval. Bot queries chunks on each message and injects
relevant past conversations into the system prompt. New exchanges are indexed
automatically after each bot response.
Memory-service: /chunks/store, /chunks/query, /chunks/bulk-store endpoints
Bot: chunk query + formatting, live indexing via asyncio.gather with memory extraction
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>