fix(whatsapp): stop reconnecting quiet sockets

Fixes #70678.\n\nKeeps quiet but healthy WhatsApp linked-device sessions connected by tracking WhatsApp Web transport activity, while retaining a longer app-silence cap so frame activity cannot mask a stuck session forever. Also cleans up transport activity listeners on failed connection-open paths.\n\nCarries forward the focused #71466 approach and keeps #63939 as related configurable-timeout follow-up. Thanks @vincentkoc and @oromeis.\n\nValidation:\n- pnpm test:serial extensions/whatsapp/src/auto-reply.web-auto-reply.connection-and-logging.e2e.test.ts extensions/whatsapp/src/connection-controller.test.ts\n- pnpm check:changed\n- codex review --base origin/main

docs/channels/whatsapp.md

@@ -146,6 +146,7 @@ OpenClaw recommends running WhatsApp on a separate number when possible. (The ch
 ## Runtime model
 
 - Gateway owns the WhatsApp socket and reconnect loop.
+- The reconnect watchdog uses WhatsApp Web transport activity, not only inbound app-message volume, so a quiet linked-device session is not restarted solely because nobody has sent a message recently. A longer application-silence cap still forces a reconnect if transport frames keep arriving but no application messages are handled for the watchdog window.
 - Outbound sends require an active WhatsApp listener for the target account.
 - Status and broadcast chats are ignored (`@status`, `@broadcast`).
 - Direct chats use DM session rules (`session.dmScope`; default `main` collapses DMs to the agent main session).
@@ -510,6 +511,10 @@ Behavior notes:
   <Accordion title="Linked but disconnected / reconnect loop">
     Symptom: linked account with repeated disconnects or reconnect attempts.
 
+    Quiet accounts can stay connected past the normal message timeout; the watchdog
+    restarts when WhatsApp Web transport activity stops, the socket closes, or
+    application-level activity stays silent beyond the longer safety window.
+
     Fix:
 
     ```bash