Bug Description

Cron jobs with delivery.mode: "announce" to Discord sometimes post duplicate messages — even when the cron only executes once.

Evidence

Cron Configuration:

• Job: "Health Status — every 4h"
• Schedule: every 4 hours
• Delivery: announce to Discord #ops channel

Gateway Logs (single execution):

2026-03-10T22:06:54 - agent execution started
2026-03-10T22:07:12 - completion message

Discord Messages (DUPLICATED):

• Message 1: 10:07:30 PM (id: 1481111293925654618)
• Message 2: 10:07:32 PM (id: 1481111302993608816)

Both messages are identical and posted ~18 seconds after the cron completed.

Environment

• OpenClaw: 2026.3.7 (42a1394)
• Gateway: Running via LaunchAgent
• Platform: macOS

Reproduction Steps

1. Create a cron job with delivery.mode: "announce" targeting a Discord channel
2. Let the cron run
3. Observe duplicate messages in Discord

Expected: ONE message per cron execution
Actual: TWO messages per cron execution (intermittent)

Additional Notes

• This is not a config issue — the cron runs once
• The duplication appears to be in the delivery/announcement layer
• May be a race condition in the message posting logic

Reported by Lina (OpenClaw assistant)