feat(leads): link consumer account to lead on submission

- user_account FK on Lead model (SET_NULL, related_name='submitted_leads')
- Migration 0004_lead_user_account
- ScheduleCallView auto-matches consumer account by email on create
- _serialize_lead now returns userAccount: {id, name, email, phone, eventifyId, profilePicture}

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

admin_api/views.py

@@ -2357,6 +2357,25 @@ def _serialize_lead(lead):
     if lead.assigned_to:
         assigned_name = lead.assigned_to.get_full_name() or lead.assigned_to.username
         assigned_id = lead.assigned_to.pk
+
+    user_account = None
+    if lead.user_account:
+        u = lead.user_account
+        profile_pic = None
+        try:
+            if u.profile_picture:
+                profile_pic = u.profile_picture.url
+        except Exception:
+            pass
+        user_account = {
+            'id':           u.pk,
+            'name':         u.get_full_name() or u.username,
+            'email':        u.email,
+            'phone':        getattr(u, 'phone_number', None) or '',
+            'eventifyId':   getattr(u, 'eventify_id', None),
+            'profilePicture': profile_pic,
+        }
+
     return {
         'id':             lead.pk,
         'name':           lead.name,
@@ -2372,6 +2391,7 @@ def _serialize_lead(lead):
         'notes':          lead.notes,
         'createdAt':      lead.created_at.isoformat(),
         'updatedAt':      lead.updated_at.isoformat(),
+        'userAccount':    user_account,
     }
 
 
@@ -2399,7 +2419,7 @@ class LeadListView(APIView):
     def get(self, request):
         from admin_api.models import Lead
         from django.db.models import Q
-        qs = Lead.objects.select_related('assigned_to').order_by('-created_at')
+        qs = Lead.objects.select_related('assigned_to', 'user_account').order_by('-created_at')
 
         # Filters
         status_f = request.query_params.get('status', '').strip()
@@ -2448,7 +2468,7 @@ class LeadDetailView(APIView):
     def get(self, request, pk):
         from admin_api.models import Lead
         from django.shortcuts import get_object_or_404
-        lead = get_object_or_404(Lead.objects.select_related('assigned_to'), pk=pk)
+        lead = get_object_or_404(Lead.objects.select_related('assigned_to', 'user_account'), pk=pk)
         return Response(_serialize_lead(lead))