feat: add social features, leaderboard, auth enhancements, and admin fixes

- Implement Social Features: Shared Tasks, Global Access, Privacy Settings (Leaderboard/Searchable).
- Add Leaderboard Page and API.
- Enhance Auth: Support Email/Username login, explicit duplicate registration errors.
- Fix: Admin login password hash regression.
- Refactor: Move to wouter for routing, add Admin Dashboard and User Management.
- Add Setup Wizard.
- Update UI with Sidebar and Gamification elements.

client/src/components/ui/calendar.tsx

@@ -16,6 +16,7 @@ function Calendar({
   return (
     <DayPicker
       showOutsideDays={showOutsideDays}
+      showWeekNumber={true}
       weekStartsOn={1}
       className={cn("p-3", className)}
       classNames={{