Add WordPress operation provider factory

[alexstandiford]

Summary

Stacked on PR44 (codex/wordpress-coordination, d502c26). Adds the WordPress adapter implementation of DB PR42's OperationDatabaseProviderFactory (4b0b770) for official core wpdb only.

• Creates fresh operation-local WordPress QueryBuilder and ClauseBuilder instances from the exact active coordinator/pinned wpdb resource before handler clause preparation.
• Refuses factory use outside the matching active coordinated callback; preserves the operation query strategy, cache/event wrappers, source logger, and independent builders.
• Binds the factory through WordPressInitializer and verifies the production container shares one ordinary/coordinated strategy instance; covers the cache TTL/database provider alias seam.
• Adds real official WordPress 6.8.3 + MySQL 8 handler-bridge coverage for rollback suppression, post-commit invalidation/events, fresh reads, callback/resource identity, and builder affinity.

The hosted MySQL 8 + official WordPress 6.8.3 integration job with --fail-on-skipped is included in the stacked PR44 coordinator layer.

Verification

• vendor/bin/phpunit --colors=never — 78 tests, 139 assertions.
• Official WP 6.8.3 + MySQL 8: vendor/bin/phpunit -c phpunit-integration.xml --colors=never --fail-on-skipped — 76 tests, 161 assertions.