Implement working cookie extraction using Tauri's IPC event system:
**How it works:**
1. Opens embedded browser window for user to login
2. User completes authentication (including SSO)
3. User clicks "Complete Login" button in UI
4. JavaScript injected into webview extracts `document.cookie`
5. Parsed cookies emitted via Tauri event: `tftsr-cookies-extracted`
6. Rust listens for event and receives cookie data
7. Cookies encrypted and stored in database
**Technical implementation:**
- Uses `window.__TAURI__.event.emit()` from injected JavaScript
- Rust listens via `app_handle.listen()` with Listener trait
- 10-second timeout with clear error messages
- Handles empty cookies and JavaScript errors gracefully
- Cross-platform compatible (no platform-specific APIs)
**Cookie limitations:**
- `document.cookie` only exposes non-HttpOnly cookies
- HttpOnly session cookies won't be captured via JavaScript
- For HttpOnly cookies, services must provide API tokens as fallback
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
Implement three authentication methods for Confluence, ServiceNow, and Azure DevOps:
1. **OAuth2** - Traditional OAuth flow for enterprise SSO environments
2. **Embedded Browser** - Webview-based login that captures session cookies/tokens
- Solves VPN constraints: users authenticate off-VPN via web UI
- Extracted credentials work on-VPN for API calls
- Based on confluence-publisher agent pattern
3. **Manual Token** - Direct API token/PAT input as fallback
**Changes:**
- Add webview_auth.rs module for embedded browser authentication
- Implement authenticate_with_webview and extract_cookies_from_webview commands
- Implement save_manual_token command with validation
- Add AuthMethod enum to support all three modes
- Add RadioGroup UI component for mode selection
- Complete rewrite of Integrations settings page with mode-specific UI
- Add secondary button variant for UI consistency
**VPN-friendly design:**
Users can authenticate via webview when off-VPN (web UI accessible), then use extracted cookies for API calls when on-VPN (API requires VPN). Addresses enterprise SSO limitations where OAuth app registration is blocked.
Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>
