feat(spring): @DataStormTest test slice

[zantvoort]

Spring users test Storm code with a full @SpringBootTest or with Storm's own @StormTest, which bypasses the Spring context entirely. What was missing is the slice test Spring users reach for first, like @DataJpaTest or @JooqTest.

Fixes #200

What's included

• New storm-spring-boot-test-autoconfigure module (mirroring Boot's own layout, where @DataJpaTest lives in spring-boot-test-autoconfigure) with @DataStormTest: starts only the DataSource, Storm's auto-configuration (template, repository scanning, transaction integration, schema validation, exception translation, observations), SQL initialization, and Flyway or Liquibase when present. Regular @Component/@Service/@Controller beans stay out via a type exclude filter honoring includeFilters/excludeFilters/useDefaultFilters; a bootstrapper applies the annotation's properties attribute.
• Transaction-per-test with rollback: the slice is meta-annotated @Transactional and includes the transaction bridge, so Storm repository writes join the Spring-managed test transaction and roll back after each test.
• Embedded database by default (Spring Boot 3), Testcontainers as opt-out: the slice imports the test-database auto-configuration, replacing the application's DataSource with an embedded database; spring.test.database.replace=none runs against the configured one, such as a Testcontainers-managed database via @ServiceConnection. On Spring Boot 4 the replacement activates when spring-boot-jdbc-test-autoconfigure is present.
• One module serves both starters: the slice pulls in the starters' identically named auto-configuration classes (the Bring the Java Spring modules to transaction parity with Kotlin #202 alignment), with Boot 3 and Boot 4 platform entries listed as optional: imports, and the type exclusion registered through a context customizer built on FQCN-stable core classes rather than @TypeExcludeFilters, which Spring Boot 4 relocated. The module has no compile dependency on Storm; one artifact serves Boot 3 and Boot 4 (verified against Spring Boot 4.1 applications).

Relationship to @stormtest

@StormTest (storm-test) remains the fast, framework-free option for query-level tests; @DataStormTest covers what production Spring code sees — injected repository beans, translated exceptions, Spring-managed transactions, storm.* configuration. The docs cross-reference both with a rule of thumb.

Verification

• Full reactor green (13,724 tests across 26 modules).
• Module tests against the Java starter: repository scanning and injection, component exclusion, active test transaction, rollback between ordered tests, exception translation active inside the slice, properties attribute applied.
• Kotlin starter smoke suite: the same annotation resolves the Kotlin starter's auto-configurations, repositories bind through the Kotlin adapter, and writes roll back per test.

Docs: "Testing with @DataStormTest" section in spring-integration.md with H2 and Testcontainers examples; cross-links between testing.md and the slice section; CHANGELOG entry. Module registered in the reactor and the BOM.