feat(add-wechat): personal WeChat channel via Tencent iLink Bot API

New channel skill for personal WeChat, using Tencent's official iLink
Bot API (the same protocol @tencent-weixin/openclaw-weixin uses).
Region-restricted to mainland 微信 accounts — international WeChat
clients can't complete the QR flow.

Skill contents:
- Install steps copy the adapter from the `channels` branch (same
  pattern as other /add-<channel> skills) and register it in
  src/channels/index.ts.
- Post-login wiring helper at scripts/wire-dm.ts — lists unwired
  WeChat messaging groups, prompts for an agent group, and inserts the
  messaging_group_agents row with sender policy `request_approval` by
  default (matches the router auto-create default so the admin gets an
  approval card on the next unknown-sender DM).
- Channel Info documents how /new-setup Claude captures the
  operator's user_id (from data/wechat/auth.json.operatorUserId) and
  the first DM's platform_id (from the adapter's "WeChat inbound" log).

Also adds WeChat as option 15 in /new-setup's channel list so setup
wires into the existing /add-<channel> flow automatically.

Addresses https://github.com/qwibitai/nanoclaw/issues/1901.

Co-Authored-By: ythx-101 <226337373+ythx-101@users.noreply.github.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.claude/skills/add-wechat/REMOVE.md

@@ -0,0 +1,49 @@
+# Remove WeChat Channel
+
+Undo `/add-wechat`.
+
+### 1. Remove credentials
+
+Delete WeChat lines from `.env`:
+
+```bash
+sed -i.bak '/^WECHAT_ENABLED=/d' .env && rm -f .env.bak
+cp .env data/env/env
+```
+
+### 2. Remove adapter and import
+
+```bash
+rm -f src/channels/wechat.ts
+sed -i.bak "/import '\.\/wechat\.js';/d" src/channels/index.ts && rm -f src/channels/index.ts.bak
+```
+
+### 3. Uninstall the package
+
+```bash
+pnpm remove wechat-ilink-client
+```
+
+### 4. Remove saved auth + sync state
+
+```bash
+rm -rf data/wechat
+```
+
+### 5. Remove DB wiring
+
+```sql
+-- Remove any sessions first (foreign key)
+DELETE FROM sessions WHERE messaging_group_id IN (SELECT id FROM messaging_groups WHERE channel_type = 'wechat');
+DELETE FROM messaging_group_agents WHERE messaging_group_id IN (SELECT id FROM messaging_groups WHERE channel_type = 'wechat');
+DELETE FROM messaging_groups WHERE channel_type = 'wechat';
+```
+
+### 6. Rebuild and restart
+
+```bash
+pnpm run build
+systemctl --user restart nanoclaw   # Linux
+# or
+launchctl kickstart -k gui/$(id -u)/com.nanoclaw   # macOS
+```