Security enhancement: Remove frontend browser phone interface

- Updated shortcode to redirect to admin browser phone page for enhanced security
- Removed frontend browser phone assets (108KB total):
  - assets/js/browser-phone-frontend.js (85KB)
  - assets/css/browser-phone-frontend.css (23KB)
- Modified shortcode to show secure redirect interface with authentication checks
- Added new shortcode attributes: title, button_text, target
- Enhanced documentation with security improvements and new behavior
- Reduced frontend attack surface by eliminating JavaScript exposure
- Improved performance with minimal asset loading for shortcode pages

🤖 Generated with [Claude Code](https://claude.ai/code)

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

README.md

@@ -46,7 +46,8 @@ This plugin **requires** the Twilio PHP SDK v8.7.0 to function. The plugin will
 - **Queue Notifications**: SMS alerts to designated numbers when calls enter queues
 
 ### 🌐 Browser Phone (WebRTC)
-- **In-Browser Calling**: Make and receive calls directly from WordPress admin or frontend
+- **Admin-Only Access**: Secure browser phone interface available only in WordPress admin area
+- **Enhanced Security**: All browser phone functionality moved from frontend for improved security
 - **Twilio Voice SDK v2**: Uses latest SDK for WebRTC functionality
 - **Visual Dialpad**: Click-to-dial interface with DTMF support
 - **Call Controls**: Mute, hold indicators, call timer
@@ -54,7 +55,7 @@ This plugin **requires** the Twilio PHP SDK v8.7.0 to function. The plugin will
 - **Queue Integration**: Accept calls from specific queues
 - **Token Management**: Automatic token refresh for uninterrupted service
 - **Mobile-Friendly**: Responsive design optimized for smartphones and tablets
-- **Shortcode Support**: Embed browser phone on any page with `[twp_browser_phone]`
+- **Shortcode Redirect**: `[twp_browser_phone]` shortcode provides secure redirect to admin interface
 
 ### 🕒 Business Hours Management
 - **Schedule-based Routing**: Different call flows for business hours vs after-hours
@@ -113,7 +114,15 @@ This plugin **requires** the Twilio PHP SDK v8.7.0 to function. The plugin will
 ## Recent Updates
 
 ### MAJOR RELEASE v2.3.0 (September 2025) - Enterprise Ready
-Comprehensive system overhaul with production-ready reliability improvements.
+Comprehensive system overhaul with production-ready reliability improvements and enhanced security.
+
+#### 🔒 Security Enhancement: Frontend Browser Phone Removal
+- **Security-First Approach**: Removed full browser phone interface from frontend shortcode
+- **Admin-Only Access**: All browser phone functionality now restricted to secure WordPress admin area
+- **Asset Reduction**: Eliminated 108KB of frontend assets (browser-phone-frontend.js and CSS)
+- **Reduced Attack Surface**: Minimized frontend JavaScript exposure and potential security vectors
+- **Performance Boost**: Improved page load times with reduced frontend asset loading
+- **Professional Redirect**: Shortcode now provides clean redirect interface to admin browser phone
 
 #### 🚀 Extension Transfer System - Complete Solution
 - **FIXED: Direct Voicemail Issue**: Extension transfers no longer go directly to voicemail for available agents
@@ -326,11 +335,16 @@ Comprehensive redesign of hold, transfer, and requeue functionality with profess
    - Enter TwiML App SID
    - Save settings
 
-3. **Access Browser Phone**:
-   - Navigate to **Twilio** → **Browser Phone**
+3. **Access Browser Phone** (Admin Only):
+   - Navigate to **WordPress Admin** → **Twilio** → **Browser Phone**
    - Select caller ID from available numbers
    - Start making/receiving calls
 
+4. **Frontend Access** (Optional):
+   - Use `[twp_browser_phone]` shortcode on any page
+   - Shortcode provides secure redirect to admin interface
+   - Requires user login and appropriate permissions
+
 ### Agent Configuration
 1. **Create Agent Groups** (Twilio → Agent Groups)
 2. **Add Agents** to groups with priorities
@@ -356,37 +370,41 @@ Comprehensive redesign of hold, transfer, and requeue functionality with profess
    - **Queue Timeouts**: Alert when calls wait too long (configurable threshold)
    - **Missed Calls**: Alert when calls are abandoned or timeout
 
-## Frontend Browser Phone
+## Browser Phone Access
 
-### Shortcode Usage
-The browser phone can be embedded on any WordPress page using the `[twp_browser_phone]` shortcode. This is perfect for creating dedicated agent pages or customer service portals.
+### Shortcode Usage (Redirect Interface)
+The `[twp_browser_phone]` shortcode now provides a **secure redirect interface** that directs users to the WordPress admin browser phone page for enhanced security.
 
 **Basic Usage:**
 ```
 [twp_browser_phone]
 ```
 
-**With Options:**
+**With Custom Options:**
 ```
-[twp_browser_phone title="Customer Service Phone" show_title="true" compact="false"]
+[twp_browser_phone title="Customer Service Phone" button_text="Access Phone System" target="_blank"]
 ```
 
 ### Shortcode Parameters
-- **title**: Custom title for the phone widget (default: "Browser Phone")
-- **show_title**: Display the title above the phone (default: "true")
-- **compact**: Use compact layout for smaller spaces (default: "false")
+- **title**: Custom title for the redirect interface (default: "Browser Phone")
+- **button_text**: Text for the admin link button (default: "Access Browser Phone")
+- **target**: Link target behavior (default: "_blank" - opens in new tab)
 
-### Permission Requirements
-- Users must be **logged in** to access the browser phone
-- Users need the **`twp_access_browser_phone`** capability or **`manage_options`**
-- Phone Agent role users have access by default
+### Security Features
+- **Authentication Required**: Users must be logged in to see the redirect interface
+- **Permission Validation**: Requires `twp_access_browser_phone` capability or `manage_options`
+- **Clear Error Messages**: Informative feedback for unauthorized access attempts
+- **Admin-Only Interface**: All browser phone functionality restricted to WordPress admin area
 
-### Mobile Optimization
-- **Responsive Design**: Adapts to all screen sizes
-- **Touch-Friendly**: Large buttons optimized for mobile devices
-- **Haptic Feedback**: Vibration on button press (where supported)
-- **Auto-Zoom Prevention**: Proper viewport handling for mobile browsers
-- **Dark Mode Support**: Automatically adapts to user's system preference
+### Browser Phone Interface (Admin Area)
+Access the full browser phone interface at: **WordPress Admin → Twilio → Browser Phone**
+
+#### Features:
+- **Enhanced Security**: Protected by WordPress admin authentication
+- **Full Functionality**: Complete browser phone features available in secure environment
+- **Responsive Design**: Adapts to all screen sizes within admin interface
+- **Professional Interface**: Integrated with WordPress admin styling
+- **No Frontend Assets**: Eliminates security risks from frontend JavaScript exposure
 
 ## Voice Configuration
 
@@ -407,10 +425,12 @@ The browser phone can be embedded on any WordPress page using the `[twp_browser_
 
 ### Common Issues
 
-#### Browser Phone "Client version not supported"
-- **Fixed in latest version**: Upgraded to Voice SDK v2
-- Clear browser cache and reload page
-- Check TwiML App SID is configured
+#### Browser Phone Access Issues
+- **Access via Admin Only**: Browser phone moved to WordPress admin area for security
+- **Shortcode Redirect**: Frontend shortcode now provides redirect to admin interface
+- **Permission Required**: Ensure user has `twp_access_browser_phone` or `manage_options` capability
+- **Login Required**: Users must be logged in to access browser phone functionality
+- Check TwiML App SID is configured in WordPress admin settings
 
 #### "Twilio SDK classes not available"
 ```bash
@@ -519,6 +539,10 @@ All webhooks are REST API endpoints under `/wp-json/twilio-webhook/v1/`:
 - **Mobile Browsers**: Limited WebRTC support
 
 ### Security Considerations
+- **Admin-Only Browser Phone**: All browser phone functionality restricted to WordPress admin area
+- **Frontend Asset Elimination**: Removed 108KB of frontend JavaScript and CSS to reduce attack surface
+- **Authentication Required**: Shortcode requires user login and appropriate permissions
+- **Secure Redirects**: Frontend shortcode provides authenticated redirect to admin interface
 - All webhooks use WordPress nonce verification
 - Phone numbers validated and sanitized
 - SQL queries use prepared statements
@@ -528,6 +552,10 @@ All webhooks are REST API endpoints under `/wp-json/twilio-webhook/v1/`:
 ## Version History
 
 ### v2.3.0 (Current - September 2025) - ENTERPRISE READY
+- **SECURITY ENHANCEMENT**: Removed frontend browser phone interface, moved to admin-only access for enhanced security
+- **ASSET REDUCTION**: Eliminated 108KB of frontend assets (browser-phone-frontend.js and CSS files)
+- **SHORTCODE SECURITY**: Browser phone shortcode now provides secure redirect with authentication checks
+- **ATTACK SURFACE REDUCTION**: Minimized frontend JavaScript exposure and potential security vectors
 - **EXTENSION TRANSFER SYSTEM**: Complete overhaul with queue-based routing, 2-minute timeout, and automatic voicemail fallback
 - **BROWSER PHONE UNIVERSAL**: Firefox support, permission management, call stability, and cross-browser compatibility
 - **AGENT STATUS AUTOMATION**: 1-minute auto-revert system with WordPress cron job integration