Fix permissions and prepare admin login for deploy

- Admin-only: list contacts, create/edit campaigns and compositions
- Public: submit contact, mine contacts by email/phone, read campaigns/compositions
- Add admin_response field on ContactUs
- Update Postman base_url to https://zoneco.org/api with token save

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

api/models.py

@@ -27,6 +27,12 @@ class ContactUs(models.Model):
         choices=CATEGORY_CHOICES,
         verbose_name='دسته‌بندی'
     )
+    admin_response = models.TextField(
+        blank=True,
+        default='',
+        verbose_name='پاسخ ادمین',
+        help_text='Admin reply visible to the contact submitter',
+    )
     created_at = models.DateTimeField(auto_now_add=True, verbose_name='تاریخ ایجاد')
     updated_at = models.DateTimeField(auto_now=True, verbose_name='تاریخ بروزرسانی')
     
@@ -37,6 +43,7 @@ class ContactUs(models.Model):
         indexes = [
             models.Index(fields=['-created_at']),
             models.Index(fields=['category']),
+            models.Index(fields=['email_or_phone']),
         ]
     
     def __str__(self):