Play Framework

fix: per-EMF JCache discovery + release notes (release 1.12.38)

Closes the M3 + L4 items from the PF-86 audit.

* JPAPlugin.bindJCacheMetrics — now per-SessionFactory rather than a
  single global iteration of the default Caching.getCachingProvider().
  Resolves the cache manager via SessionFactoryImplementor
  .getServiceRegistry().getService(RegionFactory.class), instanceof-
  guards on JCacheRegionFactory, and tags every emitted meter with
  db=<dbName>. Required for multi-tenant SaaS and read-replica setups
  where many DBs share entity classes (and therefore L2 region names);
  the previous global path collapsed those into one ambiguous series.
  Apps without L2, or with a non-JCache region factory (Infinispan,
  custom), silently fall through with debug-level logging.
* releasenotes-1.12.0.textile — expanded the Micrometer section with
  subsections covering the cache + connection-pool binders shipped in
  1.12.34 / 1.12.35 / 1.12.36 (PF-85 / PF-86 / PF-87) and the 1.12.37
  multi-DB pool naming + dev-reload tracker rebind. Calls out
  hibernate.generate_statistics=true as opt-in default (putIfAbsent
  honors app overrides) and the PF-87 javax.persistence opt-in path
  for HibernateMetrics on this jakarta-only fork.

Positive L2 test coverage requires adding caffeine-jcache to lib-test/
plus a @Cacheable test entity and L2 config to the integration testapp
— tracked as a follow-up since the existing testapp has no entities
and adding a JCache provider is a separate fixture-design choice. The
existing MetricsFunctionalTest verifies the no-L2 path doesn't regress.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>