fix(price-trigger): restrict notifications to SMS only

Remove email/in-app paths and enforce sms action on create/update so
price alerts match the product requirement for SMS-only delivery.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Http/Controllers/Customer/PriceTriggerController.php

@@ -37,6 +37,7 @@ class PriceTriggerController extends SuperController
     public function store(Request $request)
     {
         $this->sanitizeProductId($request, true);
+        $request->merge(['action' => 'sms']);
 
         return parent::store($request);
     }
@@ -44,6 +45,7 @@ class PriceTriggerController extends SuperController
     public function update(Request $request, $id)
     {
         $this->sanitizeProductId($request, false);
+        $request->merge(['action' => 'sms']);
 
         return parent::update($request, $id);
     }