Version 7.0: observers driven by the anydataset-db DatabaseExecutor

[byjg]

Summary

Version 7.0 rewires the entire observer system on top of the low-level DatabaseExecutor observer from byjg/anydataset-db 7.0, and migrates off the driver query methods removed in that release.

• ORMSubject removed: dispatch now flows through ObserverBridge, a DatabaseEventObserverInterface implementation attached one-per-DatabaseExecutor (tracked in a WeakMap — no global state, nothing to clear in tests)
• Complete coverage: every write built by MicroOrm notifies — save(), delete(), deleteByQuery(), bulkExecute() (after commit, nothing on rollback), buildAndExecute(), and built statements executed directly on the executor
• Same semantics for save(): deferred dispatch keeps notifying after key rehydration, so Insert observers still receive the entity with its generated PK
• OrmSqlStatement: every builder build() returns it, stamped with the ORM event and affected table; exposed to observers via ObserverData::getStatement()
• New ObserverEvent::SoftDelete: soft deletes now fire an event (previously silent)
• New StatementHookInterface: before-execute hook with full SQL/params access; throwing vetoes the write
• Raw observer passthrough: Repository::addObserver() also accepts a raw DatabaseEventObserverInterface; new removeObserver()
• Performance: zero observers → zero cost (no singleton call per write anymore); non-matching tables exit on a single hash check; no new SELECTs

ObserverProcessorInterface implementations require no code change. Breaking changes and the migration table are documented in CHANGELOG-7.0.md.

Breaking changes

• ORMSubject removed (including clearObservers())
• Observer scope changed from global to per-executor: repositories on different DatabaseExecutor instances no longer cross-notify
• More events fire than before (SoftDelete, bulk, direct executions)
• Repository protected helpers insert()/insertWithAutoInc()/insertWithKeyGen()/update() now receive the pre-built OrmSqlStatement
• Requires byjg/anydataset-db: ^7.0 (driver query methods removed upstream)

Test plan

• All 5 pre-existing observer tests pass with unchanged assertions (semantic gate, including generated-id visibility on insert)
• 10 new tests in tests/ObserverBridgeTest.php: soft delete event, direct executor writes, bulk commit/rollback, per-executor scoping, veto hook, getStatement(), raw passthrough, addDbDriverForWrite() re-attach, onError() swallowing
• Full suite: 336 tests, 1012 assertions, green against anydataset-db 7.0.x-dev; Psalm clean