AH subprocess Phase 3 DB: index worker journal pruning

[MadMaxMangos]

Summary

• Advance the character database from 22.5.2 to 22.5.3.
• Replace the single-column journal state index with (state, created_time) and (state, resolved_time) indexes for bounded terminal retention.
• Make each index transition conditional so the update can recover if MariaDB commits the DDL before the db_version row is inserted.

Coordination

This migration is required by mangoszero/server#444. Apply the database update before deploying or enabling the updated server and AH worker.

Validation

• Applied successfully from a clean 22.5.2 schema on MariaDB 10.11.
• Reapplied successfully from an interrupted state with the new indexes present but db_version still at 22.5.2.
• Verified db_version is 22.5.3 and both composite indexes have the expected column order.
• Passed the DB-backed AH worker journal selftest and the server database-version gate.

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