feat(provider): inbound memory-call observe log (#17 observe brick)
Structured [memory-provider] request/response logging on the memory-call path: search REQUEST (scope_filter, top_k) + RESPONSE (chunk_ids, scores, scope), plus concise entry lines on upsert_many/delete_many. Self-contained stdout handler so the lines reach the provider stdout under uvicorn. Additive observability only — no search-semantics change (AND-parity with bifrost's reference store holds). This is the first concrete brick of #17's observe half, and the lens that root-caused #295's cold-recall miss (the persist/recall scope-axis asymmetry) from the provider side.
This commit is contained in:
