feat(audit): Add automation component logging

Add audit logging to:
- WebhookHandler: connect/disconnect, receive, not_found, denied, HMAC verified
- HeartbeatMonitor: start/stop, cycle, check, fail, recover
- GmailWatcher: connect/disconnect lifecycle events

All automation events now captured in audit log with proper context

src/automation/gmail.ts

@@ -6,6 +6,7 @@ import type { GmailConfig } from '../config/schema.js';
 import type { ChannelAdapter, ChannelStatus, InboundMessage, OutboundMessage } from '../channels/types.js';
 import { parseInterval } from './heartbeat.js';
 import { sanitizeHtml } from '../utils/html.js';
+import { auditLogger } from '../audit/index.js';
 
 /** Minimal interface for the parts of ChannelRegistry we need. */
 interface ChannelLookup {
@@ -99,6 +100,7 @@ export class GmailWatcher implements ChannelAdapter {
 
     this._status = 'connected';
     console.log(`GmailWatcher: Connected (poll_interval=${this.config.poll_interval ?? '300s'})`);
+    auditLogger?.systemStart('GmailWatcher', { poll_interval: this.config.poll_interval });
   }
 
   async disconnect(): Promise<void> {
@@ -107,11 +109,12 @@ export class GmailWatcher implements ChannelAdapter {
       this.pollTimer = undefined;
     }
     if (this.watchTimer) {
-      clearInterval(this.watchTimer);
+      clearTimeout(this.watchTimer);
       this.watchTimer = undefined;
     }
     this.oauth2Client = undefined;
     this._status = 'disconnected';
+    auditLogger?.systemStop('GmailWatcher');
   }
 
   async send(peerId: string, message: OutboundMessage): Promise<void> {