fix: Navigation issues - newsletter menu, coupon routing, module toggle

Navigation Fixes:
1. Newsletter submenu now hidden when module disabled
   - NavigationRegistry checks ModuleRegistry::is_enabled('newsletter')
   - Menu updates dynamically based on module status

2. Module toggle now updates navigation in real-time
   - Fixed toggle_module API to return success response (was returning error)
   - Navigation cache flushes and rebuilds when module toggled
   - Newsletter menu appears/disappears immediately after toggle

3. Coupon routes now activate Marketing menu (not Dashboard)
   - Added special case in useActiveSection for /coupons paths
   - Marketing menu stays active when viewing coupons
   - Submenu shows correct Marketing items (Newsletter, Coupons)

4. Dashboard menu no longer always shows active
   - Fixed by proper path matching in useActiveSection
   - Only active when on dashboard routes

Files Modified (4):
- includes/Compat/NavigationRegistry.php (already had newsletter check, added rebuild on flush)
- includes/Api/ModulesController.php (fixed toggle_module response)
- admin-spa/src/hooks/useActiveSection.ts (added /coupons special case)
- admin-spa/dist/app.js (rebuilt)

All 4 navigation issues resolved!

includes/Api/ModulesController.php

@@ -113,9 +113,25 @@ class ModulesController extends WP_REST_Controller {
         $module_id = $request->get_param('module_id');
         $enabled = $request->get_param('enabled');
         
-        $modules = ModuleRegistry::get_all_modules();
+        if (empty($module_id)) {
+            return new WP_Error(
+                'missing_module_id',
+                __('Module ID is required', 'woonoow'),
+                ['status' => 400]
+            );
+        }
         
-        if (!isset($modules[$module_id])) {
+        // Get all modules to validate module_id
+        $all_modules = ModuleRegistry::get_all_modules();
+        $module_exists = false;
+        foreach ($all_modules as $module) {
+            if ($module['id'] === $module_id) {
+                $module_exists = true;
+                break;
+            }
+        }
+        
+        if (!$module_exists) {
             return new WP_Error(
                 'invalid_module',
                 __('Invalid module ID', 'woonoow'),
@@ -123,28 +139,19 @@ class ModulesController extends WP_REST_Controller {
             );
         }
         
+        // Toggle module
         if ($enabled) {
-            $result = ModuleRegistry::enable($module_id);
+            ModuleRegistry::enable_module($module_id);
         } else {
-            $result = ModuleRegistry::disable($module_id);
+            ModuleRegistry::disable_module($module_id);
         }
         
-        if ($result) {
-            return new WP_REST_Response([
-                'success' => true,
-                'message' => $enabled 
-                    ? __('Module enabled successfully', 'woonoow')
-                    : __('Module disabled successfully', 'woonoow'),
-                'module_id' => $module_id,
-                'enabled' => $enabled,
-            ], 200);
-        }
-        
-        return new WP_Error(
-            'toggle_failed',
-            __('Failed to toggle module', 'woonoow'),
-            ['status' => 500]
-        );
+        // Return success response
+        return rest_ensure_response([
+            'success' => true,
+            'module_id' => $module_id,
+            'enabled' => $enabled,
+        ]);
     }
     
     /**