fix: Apply same cache flush fix to save_gateway endpoint

✅ Toggle Working: 156ms + 57ms (PERFECT!)

Log Analysis:
- Toggling gateway tripay_briva to enabled ✅
- Current enabled: no, New enabled: yes ✅
- update_option returned: true ✅
- Set gateway->enabled to: yes ✅
- Gateway after toggle: enabled=true ✅
- Total time: 156ms (toggle) + 57ms (refetch) = 213ms 🚀

The Fix That Worked:
1. Update $gateway->settings array
2. Update $gateway->enabled property (THIS WAS THE KEY!)
3. Save to database
4. Clear cache
5. Force gateway reload

Now Applying Same Fix to Modal Save:
- Added wp_cache_flush() before fetching updated gateway
- Added debug logging to track save process
- Same pattern as toggle endpoint

Expected Result:
- Modal settings save should now persist
- Changes should appear immediately after save
- Fast performance (1-2 seconds instead of 30s)

Files Modified:
- PaymentsController.php: save_gateway() endpoint

Next: Test modal save and confirm it works!

includes/Api/PaymentsController.php

@@ -175,21 +175,32 @@ class PaymentsController extends WP_REST_Controller {
         }
         
         try {
+            // Debug: Log what we're saving
+            error_log(sprintf('[WooNooW] Saving gateway %s settings: %s', $gateway_id, json_encode($settings)));
+            
             $result = PaymentGatewaysProvider::save_gateway_settings($gateway_id, $settings);
             
             if (is_wp_error($result)) {
+                error_log(sprintf('[WooNooW] Save failed: %s', $result->get_error_message()));
                 return $result;
             }
             
-            // Return updated gateway data
+            // Clear cache before fetching updated gateway
+            wp_cache_flush();
+            
+            // Return updated gateway data (fresh from DB)
             $gateway = PaymentGatewaysProvider::get_gateway($gateway_id);
             
+            // Debug: Log success
+            error_log(sprintf('[WooNooW] Gateway %s settings saved successfully', $gateway_id));
+            
             return rest_ensure_response([
                 'success' => true,
                 'message' => 'Gateway settings saved successfully',
                 'gateway' => $gateway,
             ]);
         } catch (\Exception $e) {
+            error_log(sprintf('[WooNooW] Save exception: %s', $e->getMessage()));
             return new WP_Error(
                 'save_gateway_failed',
                 $e->getMessage(),