Five Copilot review issues + the Python 3.9 CI failure rolled into one
follow-up:
* Replace ``dict | None`` annotated assignment with a type-comment so
module load doesn't evaluate PEP 604 syntax on Python 3.9 (CI red).
* Drop ``mempalace repair rebuild`` — the CLI only ships ``mempalace
repair`` (rebuild) and ``mempalace repair-status``. Updated all
user-facing messages, docstrings, and test assertions.
* Replace ``_get_client()`` in ``tool_search`` with the safe
``_refresh_vector_disabled_flag`` probe so the fallback isn't
defeated by the very chromadb client load it's trying to avoid.
* Short-circuit ``tool_status`` to a pure-sqlite reader
(``_tool_status_via_sqlite``) when divergence is detected so wing /
room counts come back without ever opening the persistent client.
* Wrap the recency-window query in ``_bm25_only_via_sqlite`` with an
``id``-ordered fallback so legacy schemas missing ``created_at``
don't break BM25 search.
New test covers the sqlite-status short-circuit. 1409 tests pass.
When chromadb's HNSW segment freezes at a stale max_elements while
sqlite keeps accumulating embeddings, the next chromadb open segfaults
the MCP server on every tool call. Adds a pure-filesystem capacity probe
(zero chromadb interaction), a `mempalace repair-status` read-only
health check, and a BM25-only sqlite fallback so the palace stays
reachable even when vector search is unavailable.
* `hnsw_capacity_status` reads sqlite + index_metadata.pickle directly
via a tight-allowlist unpickler — no hnswlib import, no segment load.
* MCP server runs the probe at startup and after every reconnect; sets
`_vector_disabled` and routes search to the sqlite FTS5 + BM25 path.
* `tool_status` and `tool_reconnect` surface the fallback state.
* Threshold tuned for chromadb 1.5.x async-flush lag (2× sync_threshold).
Igor Lins e Silva