senior's post-demo changes: parent report in the student's own account, Jalali birth date, invoices, math-only tutor, priced quotas

- remove the family app from the root (separate parent accounts, invite codes, parental
  settings); progress.0006 drops its tables, permissions and migration history, and
  Profile.parent_phone, the two family notification types and ?userId= on
  /api/progress/nodes go with it
- GET /api/user/weekly-report: last 7 days next to the 7 before (estimated minutes,
  questions, accuracy, islands, tutor questions) for the "parent report" page
- profile birthDate in Jalali (accounts/jalali.py), ages 5-99, birthYear derived from it
- GET /api/payment/invoices; orders now snapshot list price and plan title
- tutor answers only math: server pre-filter, scope rule in the prompt (tutor-v11),
  refusal marker replaced with fixed text; self-harm gets a help line instead
- streamed answers now record token usage (it was always 0)
- daily tutor quota: AI_DAILY_QUOTA_FREE (default 3) vs Plan.ai_daily_quota
- delete_users management command for wiping test accounts across every app
- docs/ai-cost-and-guardrails.md: measured cost per question and guardrail results

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

accounts/views.py

@@ -529,6 +529,22 @@ class SetUserGradeView(APIView):
         return Response(SetGradeResponseSerializer(data).data)
 
 
+def _profile_payload(user, profile) -> dict:
+    from . import jalali
+
+    return {
+        'userId': str(user.id),
+        'phone': user.phone,
+        'name': user.name,
+        'avatar': user.avatar,
+        'isGuest': user.is_guest,
+        'gradeId': user.grade_id,
+        'birthYear': profile.birth_year,
+        'birthDate': jalali.to_string(profile.birth_date) if profile.birth_date else None,
+        'bio': profile.bio,
+    }
+
+
 class UserProfileView(APIView):
     """
     GET   /api/user/profile — اطلاعات پروفایل کاربر جاری
@@ -562,18 +578,7 @@ class UserProfileView(APIView):
         # زده می‌شه (OneToOne روی user_id جاری، نه ورودیِ خارجی).
         profile, _ = Profile.objects.get_or_create(user_id=user.id)
 
-        data = {
-            'userId': str(user.id),
-            'phone': user.phone,
-            'name': user.name,
-            'avatar': user.avatar,
-            'isGuest': user.is_guest,
-            'gradeId': user.grade_id,
-            'birthYear': profile.birth_year,
-            'parentPhone': profile.parent_phone,
-            'bio': profile.bio,
-        }
-        return Response(ProfileResponseSerializer(data).data)
+        return Response(ProfileResponseSerializer(_profile_payload(user, profile)).data)
 
     @extend_schema(
         request=UpdateProfileRequestSerializer,
@@ -589,7 +594,7 @@ class UserProfileView(APIView):
         profile, _ = Profile.objects.get_or_create(user_id=user.id)
 
         user_fields = {'name': 'name', 'avatar': 'avatar'}
-        profile_fields = {'birthYear': 'birth_year', 'parentPhone': 'parent_phone', 'bio': 'bio'}
+        profile_fields = {'birthYear': 'birth_year', 'birthDate': 'birth_date', 'bio': 'bio'}
 
         changed_user = [attr for key, attr in user_fields.items() if key in v]
         changed_profile = [attr for key, attr in profile_fields.items() if key in v]
@@ -600,6 +605,17 @@ class UserProfileView(APIView):
         for key, attr in profile_fields.items():
             if key in v:
                 setattr(profile, attr, v[key])
+        # سال و تاریخ نباید از هم جدا بیفتند: تاریخ سال را می‌سازد، و سالِ تنها
+        # (اپِ قدیمی) تاریخی را که دیگر با آن نمی‌خواند پاک می‌کند.
+        if 'birthDate' in v:
+            from . import jalali
+            profile.birth_year = jalali.from_gregorian(v['birthDate'])[0] if v['birthDate'] else None
+            changed_profile.append('birth_year')
+        elif 'birthYear' in v and profile.birth_date is not None:
+            from . import jalali
+            if jalali.from_gregorian(profile.birth_date)[0] != v['birthYear']:
+                profile.birth_date = None
+                changed_profile.append('birth_date')
 
         # update_fields: فقط همان ستون‌هایی که واقعاً عوض شده‌اند نوشته شوند تا
         # PATCH همزمان از یک دستگاهِ دیگر، فیلدهای دست‌نخورده را بازنویسی نکند.
@@ -608,15 +624,4 @@ class UserProfileView(APIView):
         if changed_profile:
             profile.save(update_fields=changed_profile)
 
-        data = {
-            'userId': str(user.id),
-            'phone': user.phone,
-            'name': user.name,
-            'avatar': user.avatar,
-            'isGuest': user.is_guest,
-            'gradeId': user.grade_id,
-            'birthYear': profile.birth_year,
-            'parentPhone': profile.parent_phone,
-            'bio': profile.bio,
-        }
-        return Response(ProfileResponseSerializer(data).data)
+        return Response(ProfileResponseSerializer(_profile_payload(user, profile)).data)