fix(core): refresh stale metadata on unchanged import

[simoncodes-ca]

Summary

• re-confirm unchanged stale translations during translation-service and verification imports
• refresh target locale baseChecksum against the current base value
• preserve update no-op behavior and avoid downgrading current verified entries

Testing

• pnpm nx test core --testFile=src/lib/import/process-resource-group.spec.ts --runInBand
• full core suite: 1,312 tests passed
• pnpm nx typecheck core
• git diff --check

Closes #104