Bug

Cron jobs with payload.model set to a different model than the agent's primary model always fall back to the agent's primary model. The docs state that job payload override has highest priority, but the code disagrees.

Environment

• OpenClaw 2026.3.28 (f9b1079)
• Agent primary model: anthropic/claude-opus-4-6
• Cron payload.model: anthropic/claude-sonnet-4-6
• Sonnet is in agents.defaults.models allowlist

Steps to reproduce

1. Configure an agent with anthropic/claude-opus-4-6 as primary model
2. Add anthropic/claude-sonnet-4-6 to agents.defaults.models allowlist
3. Create an isolated cron job with payload.model: "anthropic/claude-sonnet-4-6"
4. Run the cron job (openclaw cron run <id>)
5. Check run history — model shows claude-opus-4-6, not Sonnet

Observed behavior

Gateway logs show:

[agent/embedded] live session model switch detected before attempt for <runId>: anthropic/claude-sonnet-4-6 -> anthropic/claude-opus-4-6
[model-fallback/decision] candidate_failed, requestedModel: claude-sonnet-4-6, errorPreview: "Live session model switch requested: anthropic/claude-opus-4-6"
[model-fallback/decision] candidate_succeeded, candidateModel: claude-opus-4-6, attempt: 2

The cron correctly starts with Sonnet, but then a "live session model switch" overrides it to the agent's primary model (Opus). Sonnet is treated as a failed candidate, and Opus succeeds as fallback.

Expected behavior

Per cron-jobs.md:

Resolution priority:

1. Job payload override (highest)
2. Hook-specific defaults
3. Agent config default

payload.model should take precedence over the agent's primary model for isolated cron jobs.

Additional context

• Tested with agentId: "main" and with --clear-agent — same result both ways
• Session key is always agent:main:cron:... even without explicit agentId
• The agents.defaults.models allowlist is not the issue (no "not allowed" warning after adding Sonnet)
• The "not allowed" issue from earlier versions (2026.3.24) is separate and was fixed by adding Sonnet to the allowlist