v2: add Chat SDK channel adapters and skills for 11 platforms

Thin wrapper adapters + SKILL.md for Slack, Telegram, GitHub, Linear,
Google Chat, Teams, WhatsApp Cloud API, Resend, Matrix, Webex, iMessage.
All follow the same pattern as discord-v2.ts: readEnvFile → create*Adapter
→ createChatSdkBridge → registerChannelAdapter.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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

@@ -0,0 +1,78 @@
+---
+name: add-gchat-v2
+description: Add Google Chat channel integration to NanoClaw v2 via Chat SDK.
+---
+
+# Add Google Chat Channel (v2)
+
+This skill adds Google Chat support to NanoClaw v2 using the Chat SDK bridge.
+
+## Phase 1: Pre-flight
+
+Check if `src/channels/gchat-v2.ts` exists and the import is uncommented in `src/channels/index.ts`. If both are in place, skip to Phase 3.
+
+## Phase 2: Apply Code Changes
+
+### Install the adapter package
+
+```bash
+npm install @chat-adapter/gchat
+```
+
+### Enable the channel
+
+Uncomment the Google Chat import in `src/channels/index.ts`:
+
+```typescript
+import './gchat-v2.js';
+```
+
+### Build
+
+```bash
+npm run build
+```
+
+## Phase 3: Setup
+
+### Create Google Chat App
+
+> 1. Go to [Google Cloud Console](https://console.cloud.google.com)
+> 2. Create or select a project
+> 3. Enable the **Google Chat API**
+> 4. Go to **Google Chat API** > **Configuration**:
+>    - App name and description
+>    - Connection settings: select **HTTP endpoint URL** and set to `https://your-domain/webhook/gchat`
+> 5. Create a **Service Account**:
+>    - Go to **IAM & Admin** > **Service Accounts** > **Create Service Account**
+>    - Grant the Chat Bot role
+>    - Create a JSON key and download it
+
+### Configure environment
+
+Add the service account JSON as a single-line string to `.env`:
+
+```bash
+GCHAT_CREDENTIALS={"type":"service_account","project_id":"...","private_key":"...","client_email":"..."}
+```
+
+Sync to container: `mkdir -p data/env && cp .env data/env/env`
+
+### Build and restart
+
+```bash
+npm run build
+launchctl kickstart -k gui/$(id -u)/com.nanoclaw  # macOS
+# systemctl --user restart nanoclaw  # Linux
+```
+
+## Phase 4: Verify
+
+> Add the bot to a Google Chat space, then send a message or @mention the bot.
+
+## Removal
+
+1. Comment out `import './gchat-v2.js'` in `src/channels/index.ts`
+2. Remove `GCHAT_CREDENTIALS` from `.env`
+3. `npm uninstall @chat-adapter/gchat`
+4. Rebuild and restart