fix WhatsApp group chat support and self-message handling

Bridge: allow fromMe messages in groups, include participant field in
message queue, bind to 0.0.0.0 for network access, QR served as HTML.

Adapter: process registered group messages (route to Claude), extract
participant for user identification, fix unbound 'phone' variable.

Tested end-to-end: WhatsApp group chat with Claude working. 442 tests pass.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

HANDOFF.md

@@ -22,7 +22,7 @@
 - **Stage 10.5** (85c72e4): Rename secrets.py, enhanced /status, usage tracking
 - **Stage 11** (d1bb67a): Security Hardening — prompt injection, invocation/security logging, extended doctor
 - **Stage 12** (2d8e56d): Telegram Bot — python-telegram-bot, commands, inline keyboards, concurrent with Discord
-- **Stage 13**: WhatsApp Bridge — Baileys Node.js bridge + Python adapter, polling, CLI commands
+- **Stage 13** (80502b7 + fix): WhatsApp Bridge — Baileys Node.js bridge + Python adapter, polling, group chat, CLI commands
 
 ### Total teste: 442 PASS (zero failures)
 
@@ -45,7 +45,7 @@
    - Routes through existing router.py (same as Discord/Telegram)
    - Separate auth: whatsapp.owner + whatsapp.admins (phone numbers)
    - Private chat: admin-only (unauthorized logged to security.log)
-   - Group chat: registered chats only (skipped for now)
+   - Group chat: registered chats processed, uses group JID as channel_id
    - Commands: /clear, /status handled inline
    - Other commands and messages routed to Claude via route_message
    - Message splitting at 4096 chars