Deleted the heuristic that rewrote a record the cache held "unchanged since read" (same key and
storedAt) under the registered id, in the single-file commit and in the directory generation. It
could overwrite a record another writer changed while keeping its storedAt. A commit onto a file
now writes its batch and leaves every other record as the file holds it; a record under an id only
an arrived entry lists is refused, typed, with the file left as it was. Deleted the directory
store's _durableCatalog, a second stale-able source of arrived entries beside the manifest read
under the lease.
Tests: the lost-update probe, the two refusals that replace the restamp tests, the
arrived-overwrites-registered guard in both id orders, the content-hash tie-break against the
compatible-list order, and refusal determinism across record arrival order.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>