feat(cron): Add clear-error CLI subparser

Part of #349. Adds `hermes cron clear-error JOB_ID` command.

hermes_cli/main.py

@@ -4576,6 +4576,9 @@ For more help on a command:
     cron_run.add_argument("job_id", help="Job ID to trigger")
     cron_run.add_argument("--now", action="store_true", help="Execute immediately and wait for result (clears stale errors)")
 
+    cron_clear_error = cron_subparsers.add_parser("clear-error", help="Clear stale error state for a job")
+    cron_clear_error.add_argument("job_id", help="Job ID to clear error for")
+
     cron_remove = cron_subparsers.add_parser("remove", aliases=["rm", "delete"], help="Remove a scheduled job")
     cron_remove.add_argument("job_id", help="Job ID to remove")