Cache is the one attachment fact. AddBackingStore, the only writer, publishes it right after the
registry loan and sets it back to null in the catch, all inside its hold of both gates, so a
journal's store call during the attach is refused as it is after it (it used to stage or write
records the cache never admitted). Gate loses MaxPasses and its loop: the guessed cache's gate,
the store's gate (where Cache cannot change), then the settled cache's gate. Tests: one per store
entry point through a real attach (single-file and directory), each asserting the attaching cache
and a fresh cache agree after a flush; the second-store refusal pinned before the same-store one;
the three attach tests renamed to the published-cache shape. The old
AJournalOnTheAttachingThreadCannotWriteItsStoreCacheless is the writedoc case of the new test.
This commit builds; docs follow in the next commit.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
c66b4c9e04