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-gchat/SKILL.md

@@ -0,0 +1,92 @@
+---
+name: add-gchat-v2
+description: Add Google Chat channel integration to NanoClaw v2 via Chat SDK.
+---
+
+# Add Google Chat Channel
+
+Adds Google Chat support to NanoClaw v2 using the Chat SDK bridge.
+
+## Install
+
+v2 trunk doesn't ship channels. This skill copies the Google Chat adapter in from the `channels` branch.
+
+### Pre-flight (idempotent)
+
+Skip to **Credentials** if all of these are already in place:
+
+- `src/channels/gchat.ts` exists
+- `src/channels/index.ts` contains `import './gchat.js';`
+- `@chat-adapter/gchat` 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/gchat.ts > src/channels/gchat.ts
+```
+
+### 3. Append the self-registration import
+
+Append to `src/channels/index.ts` (skip if the line is already present):
+
+```typescript
+import './gchat.js';
+```
+
+### 4. Install the adapter package (pinned)
+
+```bash
+pnpm install @chat-adapter/gchat@4.26.0
+```
+
+### 5. Build
+
+```bash
+pnpm run build
+```
+
+## Credentials
+
+> 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`
+
+## 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**: `gchat`
+- **terminology**: Google Chat has "spaces." A space can be a group conversation or a direct message with the bot.
+- **how-to-find-id**: Open the space in Google Chat, look at the URL — the space ID is the segment after `/space/` (e.g. `spaces/AAAA...`). Or use the Google Chat API to list spaces.
+- **supports-threads**: yes
+- **typical-use**: Interactive chat — team spaces or direct messages
+- **default-isolation**: Same agent group for spaces where you're the primary user. Separate agent group for spaces with different teams or sensitive contexts.