docs(channel-skills): rewrite all 13 /add-*-v2 skills for copy-from-channels-branch pattern

Each skill now:
- Pre-flight: checks for file present + import line + dep listed (idempotent)
- git fetch origin channels
- git show origin/channels:<paths> > <paths> to copy adapter (and helpers/tests/setup-step where applicable)
- Append `import './<chan>.js';` to src/channels/index.ts
- pnpm install <pkg>@<pinned-version>
- pnpm run build

Telegram additionally copies 4 helper/test files + setup/pair-telegram.ts
and registers `'pair-telegram':` in setup/index.ts STEPS.

WhatsApp (native) additionally copies setup/whatsapp-auth.ts and
registers `'whatsapp-auth':` in setup/index.ts STEPS, installs
@whiskeysockets/baileys + qrcode + @types/qrcode pinned.

All credential / next-steps / channel-info / troubleshooting sections
preserved verbatim.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.claude/skills/add-matrix-v2/SKILL.md

@@ -7,22 +7,48 @@ description: Add Matrix channel integration to NanoClaw v2 via Chat SDK. Works w
 
 Adds Matrix support to NanoClaw v2 using the Chat SDK bridge.
 
-## Pre-flight
-
-Check if `src/channels/matrix.ts` exists and the import is uncommented in `src/channels/index.ts`. If both are in place, skip to Credentials.
-
 ## Install
 
+v2 trunk doesn't ship channels. This skill copies the Matrix adapter in from the `channels` branch.
+
+### Pre-flight (idempotent)
+
+Skip to **Credentials** if all of these are already in place:
+
+- `src/channels/matrix.ts` exists
+- `src/channels/index.ts` contains `import './matrix.js';`
+- `@beeper/chat-adapter-matrix` is listed in `package.json` dependencies
+
+Otherwise continue. Every step below is safe to re-run.
+
+### 1. Fetch the channels branch
+
 ```bash
-pnpm install @beeper/chat-adapter-matrix
+git fetch origin channels
 ```
 
-Uncomment the Matrix import in `src/channels/index.ts`:
+### 2. Copy the adapter
+
+```bash
+git show origin/channels:src/channels/matrix.ts > src/channels/matrix.ts
+```
+
+### 3. Append the self-registration import
+
+Append to `src/channels/index.ts` (skip if the line is already present):
 
 ```typescript
 import './matrix.js';
 ```
 
+### 4. Install the adapter package (pinned)
+
+```bash
+pnpm install @beeper/chat-adapter-matrix@0.2.0
+```
+
+### 5. Build
+
 ```bash
 pnpm run build
 ```