test: migrate backend suites to pytest with module coverage gate

Split backend tests into unit and integration suites, add isolated fixtures and coverage enforcement, and update CI and test documentation. Cover current authentication, content, notification, payment, media, and admin flows; fix behaviors revealed by the new tests. Validate both suites and the per-module gate against local PostgreSQL.

apps/communications/api/views.py

@@ -17,6 +17,7 @@ from apps.communications.api.schemas import (
     PushDeviceUpdateSchema,
 )
 from apps.communications.models import Announcement, AnnouncementPriority, AnnouncementType, PushNotificationDevice
+from core.api.schemas import ErrorSchema
 from core.authentication import jwt_auth
 
 communications_router = Router()
@@ -31,7 +32,7 @@ def _is_staff_user(user) -> bool:
 def list_announcements(request, published_only: bool = True):
     queryset = Announcement.objects.select_related("author").filter(is_deleted=False)
     if published_only:
-        queryset = queryset.filter(is_published=True, publish_date__lte=timezone.now())
+        queryset = queryset.filter(is_published=True).filter(Q(publish_date__isnull=True) | Q(publish_date__lte=timezone.now()))
 
     items = []
     for announcement in queryset.order_by("-created_at"):
@@ -51,22 +52,35 @@ def list_announcements(request, published_only: bool = True):
     return items
 
 
-@communications_router.get("/announcements/{announcement_id}/", response=AnnouncementSchema)
+@communications_router.get("/announcements/stats/", response={200: AnnouncementStatsSchema, 403: ErrorSchema}, auth=jwt_auth)
+def get_announcement_stats(request):
+    user = request.auth
+    if not _is_staff_user(user):
+        return 403, {"error": "Permission denied"}
+    return Announcement.objects.filter(is_deleted=False).aggregate(
+        total_announcements=Count("id"),
+        published_announcements=Count("id", filter=Q(is_published=True)),
+        draft_announcements=Count("id", filter=Q(is_published=False)),
+        urgent_announcements=Count("id", filter=Q(priority="urgent")),
+    )
+
+
+@communications_router.get("/announcements/{announcement_id}/", response={200: AnnouncementSchema, 404: ErrorSchema})
 def get_announcement(request, announcement_id: int):
     announcement = get_object_or_404(
         Announcement.objects.select_related("author").filter(is_deleted=False),
         id=announcement_id,
     )
     if not announcement.is_published and not _is_staff_user(getattr(request, "auth", None)):
-        return {"error": "Announcement not found"}, 404
+        return 404, {"error": "Announcement not found"}
     return announcement
 
 
-@communications_router.post("/announcements/", response=AnnouncementSchema, auth=jwt_auth)
+@communications_router.post("/announcements/", response={200: AnnouncementSchema, 403: ErrorSchema}, auth=jwt_auth)
 def create_announcement(request, payload: AnnouncementCreateSchema):
     user = request.auth
     if not _is_staff_user(user):
-        return {"error": "Permission denied"}, 403
+        return 403, {"error": "Permission denied"}
 
     announcement = Announcement.objects.create(
         author=user,
@@ -81,11 +95,11 @@ def create_announcement(request, payload: AnnouncementCreateSchema):
     return announcement
 
 
-@communications_router.put("/announcements/{announcement_id}/", response=AnnouncementSchema, auth=jwt_auth)
+@communications_router.put("/announcements/{announcement_id}/", response={200: AnnouncementSchema, 403: ErrorSchema}, auth=jwt_auth)
 def update_announcement(request, announcement_id: int, payload: AnnouncementCreateSchema):
     user = request.auth
     if not _is_staff_user(user):
-        return {"error": "Permission denied"}, 403
+        return 403, {"error": "Permission denied"}
 
     announcement = get_object_or_404(Announcement, id=announcement_id, is_deleted=False)
     announcement.title = payload.title
@@ -99,30 +113,16 @@ def update_announcement(request, announcement_id: int, payload: AnnouncementCrea
     return announcement
 
 
-@communications_router.delete("/announcements/{announcement_id}/", response=MessageResponseSchema, auth=jwt_auth)
+@communications_router.delete("/announcements/{announcement_id}/", response={200: MessageResponseSchema, 403: ErrorSchema}, auth=jwt_auth)
 def delete_announcement(request, announcement_id: int):
     user = request.auth
     if not _is_staff_user(user):
-        return {"error": "Permission denied"}, 403
+        return 403, {"error": "Permission denied"}
     announcement = get_object_or_404(Announcement, id=announcement_id, is_deleted=False)
-    announcement.soft_delete()
+    announcement.delete()
     return {"message": "Announcement deleted successfully"}
 
 
-@communications_router.get("/announcements/stats/", response=AnnouncementStatsSchema, auth=jwt_auth)
-def get_announcement_stats(request):
-    user = request.auth
-    if not _is_staff_user(user):
-        return {"error": "Permission denied"}, 403
-    stats = Announcement.objects.filter(is_deleted=False).aggregate(
-        total_announcements=Count("id"),
-        published_announcements=Count("id", filter=Q(is_published=True)),
-        draft_announcements=Count("id", filter=Q(is_published=False)),
-        urgent_announcements=Count("id", filter=Q(priority="urgent")),
-    )
-    return stats
-
-
 @communications_router.post("/push-devices/", response=PushDeviceSchema, auth=jwt_auth)
 def register_push_device(request, payload: PushDeviceCreateSchema):
     user = request.auth
@@ -138,7 +138,7 @@ def register_push_device(request, payload: PushDeviceCreateSchema):
     return device
 
 
-@communications_router.delete("/push-devices/", response=MessageResponseSchema, auth=jwt_auth)
+@communications_router.delete("/push-devices/", response={200: MessageResponseSchema, 404: MessageResponseSchema}, auth=jwt_auth)
 def unregister_push_device(request, device_token: str):
     user = request.auth
     try:
@@ -146,7 +146,7 @@ def unregister_push_device(request, device_token: str):
         device.delete()
         return {"message": "Device unregistered successfully"}
     except PushNotificationDevice.DoesNotExist:
-        return {"message": "Device not found"}, 404
+        return 404, {"message": "Device not found"}
 
 
 @communications_router.get("/push-devices/", response=List[PushDeviceSchema], auth=jwt_auth)