Test fix diff summary

1. worker-platform/work-order-query-repo.ts
   - Trim keyword input inside buildWorkOrderWhere before adding LIKE filters.
   - Whitespace-only keywords now add no filter and no SQL parameter.

2. db/postgres.integration.test.ts
   - Use a unique regular table for the pool-concurrency test.
   - Drop the table in finally so concurrent pool connections can see it and cleanup is deterministic.