fix(customer): lưu và trả địa chỉ khách hàng

Bảng customers chỉ có cột address nên address_1/address_2 từ form admin bị bỏ khi validate.
Thêm cột address_2, fillable, rule validate và trả đủ field địa chỉ trong CustomerResource.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/Http/Requests/CreateCustomerRequest.php

@@ -28,7 +28,8 @@ class CreateCustomerRequest extends FormRequest
             'status' => 'nullable|integer|in:0,1,2,3',
             'company' => 'nullable',
             'phone' => 'nullable',
-            'address' => 'nullable',
+            'address' => 'nullable|string|max:255',
+            'address_2' => 'nullable|string|max:255',
             'city' => 'nullable',
             'state' => 'nullable',
             'postcode' => 'nullable',

app/Http/Resources/Api/Admin/CustomerResource.php

@@ -16,6 +16,12 @@ class CustomerResource extends JsonResource
             'email'      => $this->email,
             'phone'      => $this->phone,
             'company'    => $this->company,
+            'address'    => $this->address,
+            'address_2'  => $this->address_2,
+            'city'       => $this->city,
+            'state'      => $this->state,
+            'postcode'   => $this->postcode === null ? null : (string) $this->postcode,
+            'country'    => $this->country,
             'note'       => $this->note,
             'status'     => (int) $this->status,
             'total'     => (int) $this->total,