Conform cultcache-ts to the store-composition contract, following C#:
- addBackingStore refuses, attaching nothing, when the new store would
move the home of any record type the cache already holds (for example a
store routed to "settings" attached after settings:app landed in the
generic store).
- pullAllBackingStores reads, decodes and home-checks every record before
replacing the cache's view. A record delivered by a store that is not
its home throws naming the key and both stores; nothing is admitted and
no store is written.
- A cache with zero stores is in memory: put, putEnvelope and delete no
longer throw. Once any store is attached, a type with no home still
throws.
Tests for each rule fail on 6bb41f3.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
6b117def62