Expected Behavior

When deliver: false is set on a hook mapping, no system event should be injected into the main session. The hook should complete silently.

Actual Behavior

The system event Hook <name>: <summary> is always injected into the main session when deliver: false, because the guard only checks whether delivery succeeded — not whether it was requested.

Root Cause

In src/gateway/server/hooks.ts (~line 83):

if (!result.delivered) {
  enqueueSystemEvent(`${prefix}: ${summary}`.trim(), {
    sessionKey: mainSessionKey,
  });
}

When deliver: false:

1. resolveCronDeliveryPlan (in src/cron/delivery.ts) correctly resolves to { mode: "none", requested: false }
2. Delivery is never attempted, so result.delivered is always false
3. The !result.delivered guard passes → system event fires unconditionally

Suggested Fix

Check whether delivery was explicitly disabled before injecting the system event. For example:

// Also suppress system event when delivery was explicitly disabled
if (!result.delivered && value.deliver !== false) {
  enqueueSystemEvent(`${prefix}: ${summary}`.trim(), {
    sessionKey: mainSessionKey,
  });
}

Alternatively, runCronIsolatedAgentTurn could return a deliveryRequested boolean in its result so the caller can make an informed decision.

Impact

This affects any hook with deliver: false. The main session receives a system event for every hook completion, which can cause the main session agent to announce hook results to unrelated channels (e.g., posting triage summaries to a project coordination channel instead of an audit trail channel).

Reproduction

1. Configure a hook mapping with deliver: false
2. Trigger the hook
3. Observe system event Hook <name>: <summary> injected into main session
4. Main session may then announce the summary to its active channel

Relevant Files

• src/gateway/server/hooks.ts — dispatchAgentHook, the !result.delivered guard
• src/cron/delivery.ts — resolveCronDeliveryPlan, legacy mode handling for deliver: false
• src/cron/isolated-agent/run.ts — runCronIsolatedAgentTurn, delivery dispatch