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-github/SKILL.md

@@ -0,0 +1,94 @@
+---
+name: add-github-v2
+description: Add GitHub channel integration to NanoClaw v2 via Chat SDK. PR and issue comment threads as conversations.
+---
+
+# Add GitHub Channel
+
+Adds GitHub support to NanoClaw v2 using the Chat SDK bridge. The agent participates in PR and issue comment threads.
+
+## Install
+
+v2 trunk doesn't ship channels. This skill copies the GitHub adapter in from the `channels` branch.
+
+### Pre-flight (idempotent)
+
+Skip to **Credentials** if all of these are already in place:
+
+- `src/channels/github.ts` exists
+- `src/channels/index.ts` contains `import './github.js';`
+- `@chat-adapter/github` 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/github.ts > src/channels/github.ts
+```
+
+### 3. Append the self-registration import
+
+Append to `src/channels/index.ts` (skip if the line is already present):
+
+```typescript
+import './github.js';
+```
+
+### 4. Install the adapter package (pinned)
+
+```bash
+pnpm install @chat-adapter/github@4.26.0
+```
+
+### 5. Build
+
+```bash
+pnpm run build
+```
+
+## Credentials
+
+> 1. Go to [GitHub Settings > Developer Settings > Personal Access Tokens](https://github.com/settings/tokens)
+> 2. Create a **Fine-grained token** with:
+>    - Repository access: select the repos you want the bot to monitor
+>    - Permissions: **Pull requests** (Read & Write), **Issues** (Read & Write)
+> 3. Copy the token
+> 4. Set up a webhook on your repo(s):
+>    - Go to **Settings** > **Webhooks** > **Add webhook**
+>    - Payload URL: `https://your-domain/webhook/github`
+>    - Content type: `application/json`
+>    - Secret: generate a random string
+>    - Events: select **Issue comments**, **Pull request review comments**
+
+### Configure environment
+
+Add to `.env`:
+
+```bash
+GITHUB_TOKEN=github_pat_...
+GITHUB_WEBHOOK_SECRET=your-webhook-secret
+```
+
+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**: `github`
+- **terminology**: GitHub has "repositories" containing "pull requests" and "issues." Each PR or issue comment thread is a separate conversation.
+- **how-to-find-id**: The platform ID is `owner/repo` (e.g. `acme/backend`). Each PR/issue becomes its own thread automatically.
+- **supports-threads**: yes (PR and issue comment threads are native conversations)
+- **typical-use**: Webhook/notification — the agent receives PR and issue events and responds in comment threads
+- **default-isolation**: Typically shares a session with a chat channel (e.g. Slack) so the agent can summarize PRs and respond to reviews in the same context. Use a separate agent group if the repo contains sensitive code that other channels shouldn't access.