Play Framework

test(db): add Evolutions schema-migration tests against in-memory H2 (PF-137)

Adds EvolutionsTest covering the four highest data-loss risk paths of the
Evolutions engine, driving the real engine against a fresh in-memory H2
database per test (HikariCP datasource registered in DB.datasources):

- applying pending Ups in order + play_evolutions bookkeeping (state/hash/applied_at)
- detecting a checksum mismatch after an applied script is edited on disk
- the Down/revert path (schema reverted, bookkeeping row removed)
- play_evolutions problem state after a failed mid-apply evolution

H2 is configured MODE=MYSQL;DATABASE_TO_LOWER=TRUE so its JDBC catalog
metadata matches the engine's lowercase getTables/getColumns lookups.
No production code changed.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>