chore(skills): rename add-*-v2 → add-* and drop dead v1 channel skills

Renamed 13 skill folders to drop the -v2 suffix (the v2/v1 distinction
isn't load-bearing anymore — there is no v1 runtime). Deleted the four
v1 channel skills that occupied the rename target paths (add-discord,
add-slack, add-telegram, add-whatsapp); they targeted src/v1 which is
reference-only per CLAUDE.md.

Skill content still says "v2" in places — that's a follow-up commit.

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

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

@@ -0,0 +1,91 @@
+---
+name: add-matrix-v2
+description: Add Matrix channel integration to NanoClaw v2 via Chat SDK. Works with any Matrix homeserver.
+---
+
+# Add Matrix Channel
+
+Adds Matrix support to NanoClaw v2 using the Chat SDK bridge.
+
+## 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
+git fetch origin channels
+```
+
+### 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
+```
+
+## Credentials
+
+1. Register a bot account on your Matrix homeserver (e.g., via Element)
+2. Get the homeserver URL (e.g., `https://matrix.org` or your self-hosted URL)
+3. Get an access token:
+   - In Element: **Settings** > **Help & About** > **Access Token** (advanced)
+   - Or via API: `curl -XPOST 'https://matrix.org/_matrix/client/r0/login' -d '{"type":"m.login.password","user":"botuser","password":"..."}'`
+4. Note the bot's user ID (e.g., `@botuser:matrix.org`)
+
+### Configure environment
+
+Add to `.env`:
+
+```bash
+MATRIX_BASE_URL=https://matrix.org
+MATRIX_ACCESS_TOKEN=your-access-token
+MATRIX_USER_ID=@botuser:matrix.org
+MATRIX_BOT_USERNAME=botuser
+```
+
+Sync to container: `mkdir -p data/env && cp .env data/env/env`
+
+## Next Steps
+
+If you're in the middle of `/setup`, return to the setup flow now.
+
+Otherwise, run `/manage-channels` to wire this channel to an agent group.
+
+## Channel Info
+
+- **type**: `matrix`
+- **terminology**: Matrix has "rooms." A room can be a group chat or a direct message. Rooms have internal IDs (like `!abc123:matrix.org`) and optional aliases (like `#general:matrix.org`).
+- **how-to-find-id**: In Element, click the room name > Settings > Advanced — the "Internal room ID" is the platform ID (starts with `!`). Or use a room alias like `#general:matrix.org`.
+- **supports-threads**: partial (some clients support threads, but not all — treat as no for reliability)
+- **typical-use**: Interactive chat — rooms or direct messages
+- **default-isolation**: Same agent group for rooms where you're the primary user. Separate agent group for rooms with different communities or sensitive contexts.