fix: include failed end-user CRA send jobs in retry flow

[mdiapenabc]

Description

• Extends the retry-failed flow to recover failed user-initiated CRA send jobs in addition to existing failed CRON jobs.
• This ensures system-error CRA send attempts can be retried automatically.

What Changed

• Updated retry filters in backend/src/jobs/jobs.service.ts for getFailedJobs() and hasStuckOrFailedJobs().
• Added an END_USER allowlist for retryable job types, currently including SEND_CRA_FILE.
• Updated unit test expectations in backend/src/jobs/jobs.service.spec.ts to match the new retry criteria.

How To Test

• Create a failed top-level SEND_CRA_FILE job with jobTrigger=END_USER.
• Run the retry-failed job and confirm that run is reset to RUNNING and executed.
• Verify failed top-level CRON jobs are still retried as before.