Summary

• Fixes Cron agentTurn payload delivers [object Object] to LLM instead of message string openclaw/openclaw#54579
• Cron agentTurn payload was delivering [object Object] to the LLM
• The message field contained an object that was being coerced to string instead of extracting the text content

Test plan

• Create a cron job: openclaw cron add --name "test" --every "24h" --message "Say: HELLO WORLD"
• Run: openclaw cron run <id>
• Verify the LLM receives the actual message string, not [object Object]