Add optional coordinated core wpdb strategy

[alexstandiford]

Summary

• add an opt-in coordinated query strategy for the official WordPress core wpdb class and one pinned mysqli session
• validate MySQL 8 session/profile, live InnoDB table metadata, primary identity, trigger visibility, and the coordination row before the callback
• execute operation-local reads/writes directly on the pinned handle, with table/lifetime enforcement, rollback and outcome classification, and no wpdb reconnect/replay path
• bind ordinary and coordinated aliases to the same cached strategy and remove the package-level HasDefaultTtl alias collision
• add official WordPress 6.8.3 + MySQL 8 integration coverage for commit, rollback, duplicate writes, fresh reads, resource replacement, unsupported profiles, builder lifetime, NULL predicates, and callback count

Base

Stacked on codex/wordpress-query-boundary at 496e357.

Verification

• vendor/bin/phpunit --colors=never
• WORDPRESS_ROOT=.../WordPress-6.8.3 MYSQL_HOST=127.0.0.1 MYSQL_PORT=32773 MYSQL_USER=root MYSQL_PASSWORD=root MYSQL_DATABASE=nomad_coordination_fixture vendor/bin/phpunit -c phpunit-integration.xml --colors=never

The reusable database-handler/provider bridge and application publication/cache suppression remain a follow-up dependency. This PR only supplies the optional WordPress adapter/query boundary.