Play Framework

fix(jpa): evict the whole second-level cache after a fixture load (PF-190)

Fixtures.deleteDatabase() deletes with plain SQL, which Hibernate never
sees, and JPAPlugin.afterFixtureLoad() cleared only each entity manager.
The shared second-level cache kept the deleted rows, so finding a
remembered id returned an entity whose row was gone (JClaw's JF-24, where
the insert that referenced it then failed on the foreign key).
afterFixtureLoad() now also calls Hibernate's evictAllRegions() on every
persistence unit. Not JPA's Cache.evictAll(): Hibernate's evicts entity
data alone and leaves cached collections and query results stale. The
eviction covers the whole JVM, which the testing manual now says.

Guarded by integration.FixturesSecondLevelCacheTest. The fixture app now
has a second-level and query cache for it: MapRegionFactory, a map per
region, since the framework ships no JCache provider, over the
@Cache-annotated CachedShelf and CachedBook.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>