Problem

When a WhatsApp Web disconnect occurs (408/503), messages sent during the ~3-5 second reconnection window are silently dropped. The agent receives no error feedback and believes the message was delivered.

Observed behavior:

• WhatsApp gateway disconnects (status 408)
• Gateway reconnects automatically (~3-5 seconds)
• Agent's reply is generated during this window
• sendWithRetry in deliver-reply.ts tries 3 times with short backoffs (500ms/1s/1.5s = 3s total)
• All retries fail with 'Connection Closed' because reconnection takes longer
• onError callback in process-message.ts logs the error and swallows it
• Agent continues as if message was sent successfully
• User never receives the reply

Log evidence:

WhatsApp gateway disconnected (status 408)
WhatsApp gateway connected.
Failed sending web auto-reply to <jid>: Connection Closed

Related: #2983 (same root issue, closed as stale without fix)

Root Cause

Two issues in the delivery pipeline:

1. src/web/auto-reply/deliver-reply.ts — sendWithRetry() maxAttempts=3 with linear backoff (500ms × attempt). Total retry window ~3s, but reconnection takes ~3-5s. Retries are exhausted before connection is restored.

2. src/web/auto-reply/monitor/process-message.ts — onError callback only logs the error. No re-queue, no delivery failure notification to the agent, no system event.

Suggested Fix

1. Increase sendWithRetry attempts from 3→5 and backoff from 500*attempt → 1000*attempt ms (total window ~10s, covers reconnection)
2. Surface delivery failures as system events so the agent knows the message wasn't delivered

Environment

• OpenClaw v0.40.4
• WhatsApp Web via Baileys
• Ubuntu/Linux VPS