feat(src/dashboard/views): annotate ticket metrics

Introduce aggregated ticket counts to eliminate redundant queries and boost performance.

src/dashboard/views/timeline.py

@@ -1,6 +1,7 @@
 from datetime import date
 
 from django.contrib.auth import get_user_model
+from django.db.models import Count, Q
 from django.shortcuts import render
 from django.views.decorators.http import require_http_methods
 
@@ -30,6 +31,17 @@ def project_timeline_widget(request):
         qs = qs.order_by("start_date")
 
     today = date.today()
+
+    qs = qs.annotate(
+        ticket_total=Count("tickets"),
+        ticket_completed=Count("tickets", filter=Q(tickets__status__is_completed=True)),
+        ticket_overdue=Count(
+            "tickets",
+            filter=Q(tickets__due_date__lt=today)
+            & ~Q(tickets__status__is_completed=True),
+        ),
+    )
+
     timeline_data = []
 
     for p in qs.select_related():
@@ -73,11 +85,9 @@ def project_timeline_widget(request):
             remaining_text = "Due today"
 
         ticket_counts = {
-            "total": p.tickets.count(),
-            "completed": p.tickets.filter(status__is_completed=True).count(),
-            "overdue": p.tickets.filter(due_date__lt=today)
-            .exclude(status__is_completed=True)
-            .count(),
+            "total": p.ticket_total,
+            "completed": p.ticket_completed,
+            "overdue": p.ticket_overdue,
         }
 
         timeline_data.append(