docs: add Qwen OAuth auth URL (portal.qwen.ai)

- Add browser auth URL for re-authentication
- Clarify auth vs refresh vs API endpoints

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/claw-setup/README.md

@@ -272,9 +272,10 @@ Qwen Code stores OAuth credentials in `~/.qwen/oauth_creds.json`:
 
 | Endpoint | URL |
 |----------|-----|
-| **API Base** | `https://dashscope.aliyuncs.com/compatible-mode/v1` |
-| **Chat Completions** | `https://dashscope.aliyuncs.com/compatible-mode/v1/chat/completions` |
+| **Auth (Browser)** | `https://portal.qwen.ai` |
 | **Token Refresh** | `https://chat.qwen.ai/api/v1/oauth2/token` |
+| **API Base** | `https://dashscope.aliyuncs.com/compatible-mode/v1` |
+| **Chat Completions** | `/chat/completions` |
 
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