3f0cfd5ed4
Four more MCP handlers iterate a metadata list and call m.get(...)
unconditionally. When the cache contains a None entry (drawers with no
metadata, common on older mining paths), the try block catches the
AttributeError and marks the response "partial: true" with an
error message — visible as {"error": "'NoneType' object has no
attribute 'get'", "partial": true} returned from mempalace_status even
though the palace data is otherwise fetchable.
Same m = m or {} guard we applied to searcher.py (d3a2d22, a51c3c2)
and miner.status() (66f08a1). None-metadata drawers now roll up under
the existing "unknown" fallback bucket instead of poisoning the
response with a misleading partial flag.
Regression test: mock the metadata cache with a None in the middle,
assert tool_status returns clean counts and no error/partial fields.
Verified the test fails without the guard.
998 tests pass.