_readHoldingIds and the pull's Holds walk are removed in the same commit that adds
SingleFileBackingStore.CopiedHoldIds: under the store's lock, while the header on disk is
unmarked, every plain copied record the writer's registry claims and whose type reaches an
object list is decoded, and the first holding an id marks the store. Positive-only, never
refuses a write. CultMesh's typed write attaches the registry its payload was encoded with;
the raw write attaches none. Contract text states the rule and its residual.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
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