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-linear-v2/SKILL.md

@@ -0,0 +1,77 @@
+---
+name: add-linear-v2
+description: Add Linear channel integration to NanoClaw v2 via Chat SDK. Issue comment threads as conversations.
+---
+
+# Add Linear Channel (v2)
+
+This skill adds Linear support to NanoClaw v2 using the Chat SDK bridge. The agent can participate in issue comment threads.
+
+## Phase 1: Pre-flight
+
+Check if `src/channels/linear-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/linear
+```
+
+### Enable the channel
+
+Uncomment the Linear import in `src/channels/index.ts`:
+
+```typescript
+import './linear-v2.js';
+```
+
+### Build
+
+```bash
+npm run build
+```
+
+## Phase 3: Setup
+
+### Create Linear credentials
+
+> 1. Go to [Linear Settings > API](https://linear.app/settings/api)
+> 2. Create a **Personal API Key** (or use an OAuth application for team-wide access)
+> 3. Copy the API key
+> 4. Set up a webhook:
+>    - Go to **Settings** > **API** > **Webhooks** > **New webhook**
+>    - URL: `https://your-domain/webhook/linear`
+>    - Select events: **Comment** (created, updated)
+>    - Copy the signing secret
+
+### Configure environment
+
+Add to `.env`:
+
+```bash
+LINEAR_API_KEY=lin_api_...
+LINEAR_WEBHOOK_SECRET=your-webhook-secret
+```
+
+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
+
+> @mention the bot in a Linear issue comment. The bot should respond within a few seconds.
+
+## Removal
+
+1. Comment out `import './linear-v2.js'` in `src/channels/index.ts`
+2. Remove `LINEAR_API_KEY` and `LINEAR_WEBHOOK_SECRET` from `.env`
+3. `npm uninstall @chat-adapter/linear`
+4. Rebuild and restart