some improve for sms delivery

tests/e2e/test_chat_coach.py

@@ -3,6 +3,7 @@ from django.urls import reverse
 
 from apps.accounts.models import User
 from apps.customers.models import CustomerProfile
+from apps.messaging.models import Message
 from apps.staff.models import StaffProfile
 from apps.tickets.models import TicketCategory
 from apps.tickets.services import create_ticket
@@ -76,3 +77,32 @@ def test_staff_sees_chat_guidance_after_two_rapid_replies(live_server, browser_p
         conversation.send_reply("پاسخ سوم کارشناس")
         conversation.expect_guidance_visible()
         conversation.dismiss_guidance()
+
+
+def test_customer_mobile_composer_never_covers_latest_message(live_server, browser_page):
+    category = TicketCategory.objects.create(title="مکاتبات موبایل", slug="e2e-customer-mobile-composer")
+    customer = User.objects.create_user(
+        username="e2e-mobile-customer",
+        mobile="09120009021",
+        password=PASSWORD,
+        account_type=User.AccountType.CUSTOMER,
+    )
+    CustomerProfile.objects.create(user=customer, first_name="مشتری", last_name="موبایل")
+    staff = User.objects.create_user(
+        username="e2e-mobile-staff",
+        mobile="09120009022",
+        account_type=User.AccountType.STAFF,
+    )
+    StaffProfile.objects.create(user=staff, display_name="کارشناس موبایل")
+    ticket = create_ticket(customer=customer, category=category, subject="کنترل composer مشتری", body="پیام آغازین")
+    for index in range(24):
+        Message.objects.create(ticket=ticket, author=staff, body=f"پاسخ طولانی کارشناس شماره {index + 1}")
+
+    with browser_page() as page:
+        page.set_viewport_size({"width": 390, "height": 844})
+        AuthenticationPage(page, live_server.url).login_customer(customer, PASSWORD)
+        conversation = TicketConversationPage(page, live_server.url)
+        conversation.goto(reverse("tickets:detail", args=[ticket.public_id]))
+        conversation.expect_latest_message_above_composer()
+        conversation.open_composer()
+        conversation.expect_latest_message_above_composer()