Cut 5 (Python). stores_by_type maps each type to one store and generic_stores
becomes a single generic_store. add_backing_store raises on a type already
claimed and add_generic_store on a second generic store; a refused
registration claims nothing.
_stores_for_type and _all_specific_stores are deleted. _store_for_type returns
the home store and raises when stores are attached but none is home to the
type. It returns None only for a cache with no stores, which the contract
keeps as an in-memory cache. put, put_envelope, put_envelopes and delete each
write one store; pull_all_backing_stores pulls each distinct store once.
Tests: test_second_generic_store_rejected, test_type_claimed_twice_rejected,
test_types_route_to_home_store. No bytes change.
Version 0.2.0 -> 0.3.0.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
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