feat(bookings): improve admin booking wizard and user dashboard

Backend:
- Enriched GetAllUserBookings response with calculated total_amount,
  amount_paid, and duration_minutes.
- Refactored GetBookingHandler to return a flat booking object matching
  frontend expectations.
- Added account_role to admin user list response and sorted users by
  booking activity.
- Corrected function name oo to AdminCreateBookingForUserHandler.

Frontend:
- Rebuilt BookingCreateModal into a 4-step wizard supporting guest
  bookings, service overrides, and real-time availability checks.
- Fixed account dashboard logic to correctly identify upcoming vs past
  bookings and sort unpaid items to the top.
- Extracted booking flow into a shared BookingFlow component.
- Redirected admin users from home page to /today.

backend/main.go

@@ -133,8 +133,8 @@ func main() {
 				r.Get("/user/{user_id}", bookings.GetAllBookingsByUserHandler)
 				r.Get("/{id}", bookings.GetAdminBookingHandler)
 				r.Put("/{id}/progress", bookings.ProgressBookingHandler)
-				r.Post("/{id}/confirm", bookings.ConfirmBookingHandler)
-				r.Post("/{id}/cancel", bookings.ConfirmBookingHandler) // todo
+				r.Post("/{id}/confirm", bookings.ConfirmBookingHandler) // HERE
+				r.Post("/{id}/cancel", bookings.ConfirmBookingHandler)
 			})
 
 			r.Route("/admin/users", func(r chi.Router) {