fix: Match Customer Channels to Staff layout and fix event filtering

## 🐛 Bug Fixes

### Customer/Channels.tsx
- ✅ Matched layout to Staff Channels
- ✅ Added "Extend with Addons" section
- ✅ WhatsApp, Telegram, SMS addon cards
- ✅ Consistent UI with Staff page
- ✅ Removed confusing SMS "Coming Soon" inline card

### NotificationsController.php
- ✅ Fixed `get_staff_events()` filtering logic
- ✅ Fixed `get_customer_events()` filtering logic
- ✅ Now uses `recipient_type` field instead of `reset()` on channels
- ✅ Customer events will now show correctly

### Issues Fixed
1. ❌ Customer Channels inconsistent with Staff → ✅ Now matches
2. ❌ Customer Events showing "No Events" → ✅ Now filters correctly

---

**Result:** Both Staff and Customer pages now have consistent UI and working event filtering! 🎉

includes/Api/NotificationsController.php

@@ -317,12 +317,11 @@ class NotificationsController {
 	public function get_staff_events(WP_REST_Request $request) {
 		$all_events = $this->get_all_events();
 		
-		// Filter events where default recipient is 'admin' or 'staff'
+		// Filter events where recipient_type is 'staff'
 		$staff_events = [];
 		foreach ($all_events as $category => $events) {
 			$filtered = array_filter($events, function($event) {
-				$first_channel = reset($event['channels']);
-				return in_array($first_channel['recipient'] ?? 'admin', ['admin', 'staff']);
+				return ($event['recipient_type'] ?? 'staff') === 'staff';
 			});
 			
 			if (!empty($filtered)) {
@@ -342,12 +341,11 @@ class NotificationsController {
 	public function get_customer_events(WP_REST_Request $request) {
 		$all_events = $this->get_all_events();
 		
-		// Filter events where default recipient is 'customer'
+		// Filter events where recipient_type is 'customer'
 		$customer_events = [];
 		foreach ($all_events as $category => $events) {
 			$filtered = array_filter($events, function($event) {
-				$first_channel = reset($event['channels']);
-				return ($first_channel['recipient'] ?? 'admin') === 'customer';
+				return ($event['recipient_type'] ?? 'staff') === 'customer';
 			});
 			
 			if (!empty($filtered)) {