All changes are already in place and verified:

- **Build**: passes
- **go vet**: passes  
- **Tests**: pass

The changes are currently unstaged. All 16 locations from the plan have been fixed — `defer rows.Close()` added after each `Query()` error check, manual `rows.Close()` calls in error paths removed, and `rows.Err()` checks added where missing. The `AddJobCount` function was also simplified from `Query` + loop to `QueryRow().Scan()` since it returns a single value.