fix(cron): share isolated announce flow + harden cron scheduling/delivery (#11641)

* fix(cron): comprehensive cron scheduling and delivery fixes

- Fix delivery target resolution for isolated agent cron jobs
- Improve schedule parsing and validation
- Add job retry logic and error handling
- Enhance cron ops with better state management
- Add timer improvements for more reliable cron execution
- Add cron event type to protocol schema
- Support cron events in heartbeat runner (skip empty-heartbeat check,
  use dedicated CRON_EVENT_PROMPT for relay)

* fix: remove cron debug test and add changelog/docs notes (#11641) (thanks @tyler6204)

docs/automation/cron-jobs.md

@@ -464,6 +464,13 @@ openclaw system event --mode now --text "Next heartbeat: check battery."
 - Check the Gateway is running continuously (cron runs inside the Gateway process).
 - For `cron` schedules: confirm timezone (`--tz`) vs the host timezone.
 
+### A recurring job keeps delaying after failures
+
+- OpenClaw applies exponential retry backoff for recurring jobs after consecutive errors:
+  30s, 1m, 5m, 15m, then 60m between retries.
+- Backoff resets automatically after the next successful run.
+- One-shot (`at`) jobs disable after a terminal run (`ok`, `error`, or `skipped`) and do not retry.
+
 ### Telegram delivers to the wrong place
 
 - For forum topics, use `-100…:topic:<id>` so it’s explicit and unambiguous.

docs/cli/cron.md

@@ -21,6 +21,8 @@ output internal. `--deliver` remains as a deprecated alias for `--announce`.
 
 Note: one-shot (`--at`) jobs delete after success by default. Use `--keep-after-run` to keep them.
 
+Note: recurring jobs now use exponential retry backoff after consecutive errors (30s → 1m → 5m → 15m → 60m), then return to normal schedule after the next successful run.
+
 ## Common edits
 
 Update delivery settings without changing the message: