The migration was incorrectly named as v4.0→v4.1 but was actually performing
the v4.1→v4.2 migration (moving thresholds from UPS-level to action-level).
This meant users upgrading from v4.1 would not get their configs migrated.
Changes:
- Renamed migration file from migration-v4.0-to-v4.1.ts to migration-v4.1-to-v4.2.ts
- Updated class name from MigrationV4_0ToV4_1 to MigrationV4_1ToV4_2
- Updated fromVersion from '4.0' to '4.1'
- Updated toVersion from '4.1' to '4.2'
- Updated shouldRun() to check for config.version === '4.1'
- Updated all imports and exports to reference the new class name
- Updated comments and log messages to reflect v4.1→v4.2 migration
