Discrepancy between spec and Body, reported per Hands' brief ("make the
smallest change that keeps the spec's intent, and report the discrepancy").
R-R says "recordKeys: [] answers empty" for v0 lowering. That holds for the
raw v0 wire protocol server (CultNetDocumentRegistry.CreateRawSnapshotResponse,
CultNetDatabase.CreateShardSnapshotResponse - fixed two commits back). It does
not hold for CultMesh's typed convenience API: R-F, landed earlier in this
cut, made CultMesh.EnsureV0Compatible run CultNetSelectionValidation.
ValidateShape client-side before a request is ever sent, specifically so that
"Keys=[]/[\"\"] is refused rather than silently lowered to 'every key'"
(CultMeshSnapshots.cs:836-841). Once R-R made ResolveDefaultSelection's
Clean(recordKeys) produce Keys=[] instead of Keys=null for an explicit empty
list, every FetchDocumentsAsync(recordKeys: []) call now trips that existing
R-F door and throws, instead of reaching the wire at all.
Kept both rulings as each one's own owner decided them: the raw wire protocol
answers empty (R-R); CultMesh's typed wrapper refuses before sending (R-F).
Rewrote FetchDocumentsAsync_WithExplicitEmptyRecordKeys_AnswersEmpty, added
two commits ago on the wrong assumption that CultMesh's typed API also
answers empty, to FetchDocumentsAsync_WithExplicitEmptyRecordKeys_
IsRefusedClientSide, asserting the actual (and, on inspection, correct) R-F
behaviour instead.
Verified on Yggdrasil: dotnet test tests/GameCult.Mesh.Tests -c Release.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>