fix(cronjob): warn when builtin scheduler has no gateway

[zhao0112]

Summary

• Add a creation-time warning when cronjob jobs are created with the builtin scheduler but no gateway process is running.
• Preserve existing local-delivery warning behavior and keep the warning optional/non-blocking.

Changes

• tools/cronjob_tools.py
  • Added _gateway_not_running_warning() to detect resolve_cron_scheduler().name == "builtin" and no running gateway PID.
  • Appended this warning (when applicable) to the cronjob create response message alongside existing local-delivery notice.
  • Added debug logging on scheduler/pid resolution failures instead of swallowing silently.
• tests/tools/test_cronjob_tools.py
  • Added regression tests covering:
    • builtin scheduler with no gateway emits warning,
    • non-builtin scheduler omits warning,
    • running gateway omits warning.

Test Plan

• python3 -m py_compile tools/cronjob_tools.py tests/tools/test_cronjob_tools.py
• python3 -m pytest tests/tools/test_cronjob_tools.py::TestLocalDeliveryNotice::test_builtin_scheduler_without_gateway_emits_warning tests/tools/test_cronjob_tools.py::TestLocalDeliveryNotice::test_non_builtin_scheduler_omits_gateway_warning tests/tools/test_cronjob_tools.py::TestLocalDeliveryNotice::test_running_gateway_omits_warning tests/tools/test_cronjob_tools.py::TestUnifiedCronjobTool::test_create_and_list -q

Closes #87033

[alt-glitch]

This was generated by AI during triage.

Duplicate of #51790, the earlier open PR implementing the same builtin-scheduler/no-gateway creation warning and external-scheduler suppression.

[Enough1122]

AI code review — automated review for reference, author can ignore or act on any point.

fix(cronjob): warn when builtin scheduler has no gateway

1. Emoji in tool output: the warning string uses ⚠ (tools/cronjob_tools.py line 399). Tool JSON output can be rendered on plain-text gateway platforms (Telegram/SMS/email) where the emoji may garble or look broken; a plain [WARNING] prefix would be more robust across surfaces. Minor.
2. Exception swallowing: both resolve_cron_scheduler() and find_gateway_pids() failures are logged at debug and silently downgraded to "no warning" (lines 382-392) — fine for an advisory path, but note that a broken find_gateway_pids (e.g. permission error reading /proc) would hide a real "jobs won't fire" condition. Acceptable given the warning is best-effort.
3. Race with late gateway start: the warning fires at job creation time only; a user creating a job from the CLI while the gateway is down gets the warning even if they intend to start the gateway next. Advisory text is appropriate — no change needed, just confirming the message wording ("won't fire automatically") correctly avoids over-claiming.
4. Tests cover all three branches (builtin+no gateway, non-builtin, gateway running) with a clean scheduler stub — good.

[kshitijk4poor]

Closing as duplicate — merged via #88323 which salvages #73877 (the more complete implementation with a shared cron/scheduler_readiness.py module).

Your PR's approach was correct (detect builtin scheduler + no gateway → warn), and your tests covered the right branches. #73877 went further by extracting the logic into a shared module so both the CLI and the tool use the same code, avoiding future duplication. The salvage also adds a fix for the desktop ticker false positive (HERMES_DESKTOP=1 runs its own cron ticker without a gateway process).

Thank you for the contribution!