feat: Implement API and UI for toggling Claude CLI between proxy and paid modes

README.md

@@ -132,7 +132,10 @@ You can configure these settings in two ways:
 
 1. Open the WebUI at `http://localhost:8080`.
 2. Go to **Settings** → **Claude CLI**.
-3. Select your preferred models and click **Apply to Claude CLI**.
+3. Use the **Connection Mode** toggle to switch between:
+   - **Proxy Mode**: Uses the local proxy server (Antigravity Cloud Code). Configure models, base URL, and presets here.
+   - **Paid Mode**: Uses the official Anthropic Credits directly (requires your own subscription). This hides proxy settings to prevent accidental misconfiguration.
+4. Click **Apply to Claude CLI** to save your changes.
 
 > [!TIP] > **Configuration Precedence**: System environment variables (set in shell profile like `.zshrc`) take precedence over the `settings.json` file. If you use the Web Console to manage settings, ensure you haven't manually exported conflicting variables in your terminal.
 
@@ -221,6 +224,18 @@ claude
 
 > **Note:** If Claude Code asks you to select a login method, add `"hasCompletedOnboarding": true` to `~/.claude.json` (macOS/Linux) or `%USERPROFILE%\.claude.json` (Windows), then restart your terminal and try again.
 
+### Proxy Mode vs. Paid Mode
+
+Toggle in **Settings** → **Claude CLI**:
+
+| Feature | 🔌 Proxy Mode | 💳 Paid Mode |
+| :--- | :--- | :--- |
+| **Backend** | Local Server (Antigravity) | Official Anthropic Credits |
+| **Cost** | Free (Google Cloud) | Paid (Anthropic Credits) |
+| **Models** | Claude + Gemini | Claude Only |
+
+**Paid Mode** automatically clears proxy settings so you can use your official Anthropic account directly.
+
 ### Multiple Claude Code Instances (Optional)
 
 To run both the official Claude Code and Antigravity version simultaneously, add this alias: