Fix overdue calculation to use user's timezone

Tasks were incorrectly showing as overdue when they were due today.
The issue was that the overdue check was comparing the due date
against UTC's "today" instead of the user's local "today".

Now uses the user's timezone setting to determine the current date
when checking if a task is overdue. This ensures tasks due "today"
only become overdue when the user's local date advances to tomorrow.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tasks/views.py

@@ -218,7 +218,11 @@ class DashboardView(View):
         if not request.user.is_authenticated:
             return redirect('login')
 
-        today = timezone.now().date()
+        # Get today's date in user's timezone
+        import pytz
+        user_tz = pytz.timezone(request.user.timezone)
+        user_now = timezone.now().astimezone(user_tz)
+        today = user_now.date()
 
         # Get filter parameters
         current_filter = request.GET.get('filter', 'all')