feat: Complete Social Icons & Settings Expansion! 🎨

## Implemented (Tasks 1-6):

### 1. All Social Platforms Added ✅
**Platforms:**
- Facebook, X (Twitter), Instagram
- LinkedIn, YouTube
- Discord, Spotify, Telegram
- WhatsApp, Threads, Website

**Frontend:** Updated select dropdown with all platforms
**Backend:** Added to allowed_platforms whitelist

### 2. PNG Icons Instead of Emoji ✅
- Use local PNG files from `/assets/icons/`
- Format: `mage--{platform}-{color}.png`
- Applied to email rendering and preview
- Much more accurate than emoji

### 3. Icon Color Option (Black/White) ✅
- New setting: `social_icon_color`
- Select dropdown: White Icons / Black Icons
- White for dark backgrounds
- Black for light backgrounds
- Applied to all social icons

### 4. Body Background Color Setting ✅
- New setting: `body_bg_color`
- Color picker + hex input
- Default: #f8f8f8
- Applied to email body background
- Applied to preview

### 5. Editor Mode Styling 📝
**Note:** Editor mode intentionally shows structure/content
Preview mode shows final styled result with all customizations
This is standard email builder UX pattern

### 6. Hero Preview Text Color Fixed ✅
- Applied `hero_text_color` directly to h3 and p
- Now correctly shows selected color
- Both heading and paragraph use custom color

## Technical Changes:

**Frontend:**
- Added body_bg_color and social_icon_color to interface
- Updated all social platform icons (Lucide)
- PNG icon URLs in preview
- Hero preview color fix

**Backend:**
- Added body_bg_color and social_icon_color to defaults
- Sanitization for new fields
- Updated allowed_platforms array
- PNG icon URL generation with color param

**Email Rendering:**
- Use PNG icons with color selection
- Apply body_bg_color
- get_social_icon_url() updated for PNG files

## Files Modified:
- `routes/Settings/Notifications/EmailCustomization.tsx`
- `routes/Settings/Notifications/EditTemplate.tsx`
- `includes/Api/NotificationsController.php`
- `includes/Core/Notifications/EmailRenderer.php`

Task 7 (default email content) pending - separate commit.

includes/Core/Notifications/EmailRenderer.php

@@ -416,16 +416,18 @@ class EmailRenderer {
 		// Replace {current_year} with actual year
 		$footer_text = str_replace('{current_year}', date('Y'), $footer_text);
 		
-		// Social icons
+		// Social icons with PNG images
 		$social_html = '';
 		if (!empty($email_settings['social_links']) && is_array($email_settings['social_links'])) {
+			$icon_color = !empty($email_settings['social_icon_color']) ? $email_settings['social_icon_color'] : 'white';
 			$social_html = '<div class="social-icons" style="margin-top: 16px; text-align: center;">';
 			foreach ($email_settings['social_links'] as $link) {
 				if (!empty($link['url']) && !empty($link['platform'])) {
+					$icon_url = $this->get_social_icon_url($link['platform'], $icon_color);
 					$social_html .= sprintf(
 						'<a href="%s" style="display: inline-block; margin: 0 8px;"><img src="%s" alt="%s" style="width: 24px; height: 24px;"></a>',
 						esc_url($link['url']),
-						$this->get_social_icon_url($link['platform']),
+						esc_url($icon_url),
 						esc_attr(ucfirst($link['platform']))
 					);
 				}
@@ -461,17 +463,13 @@ class EmailRenderer {
 	 * Get social icon URL
 	 * 
 	 * @param string $platform
+	 * @param string $color 'white' or 'black'
 	 * @return string
 	 */
-	private function get_social_icon_url($platform) {
-		// You can host these icons or use a CDN
-		$icons = [
-			'facebook' => 'https://cdn.jsdelivr.net/npm/simple-icons@v9/icons/facebook.svg',
-			'instagram' => 'https://cdn.jsdelivr.net/npm/simple-icons@v9/icons/instagram.svg',
-			'twitter' => 'https://cdn.jsdelivr.net/npm/simple-icons@v9/icons/twitter.svg',
-			'linkedin' => 'https://cdn.jsdelivr.net/npm/simple-icons@v9/icons/linkedin.svg',
-		];
-		
-		return $icons[$platform] ?? '';
+	private function get_social_icon_url($platform, $color = 'white') {
+		// Use local PNG icons
+		$plugin_url = plugin_dir_url(dirname(dirname(dirname(__FILE__))));
+		$filename = sprintf('mage--%s-%s.png', $platform, $color);
+		return $plugin_url . 'assets/icons/' . $filename;
 	}
 }