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.

frontend/src/lib/components/booking/ServiceCard.svelte

@@ -0,0 +1,48 @@
+<script lang="ts">
+	import type { Service } from '$lib/types/booking';
+
+	let {
+		service,
+		selected = false,
+		onclick
+	}: {
+		service: Service;
+		selected?: boolean;
+		onclick?: () => void;
+	} = $props();
+</script>
+
+<button
+	type="button"
+	class="cursor-pointer rounded-lg border border-input bg-background p-4 text-left transition-colors hover:bg-fuchsia-50 hover:text-accent-foreground {selected
+		? 'bg-fuchsia-100'
+		: ''}"
+	onclick={() => onclick?.()}
+>
+	<div class="flex items-start justify-between">
+		<div class="flex-1">
+			<h3 class="font-semibold">{service.name}</h3>
+			<p class="text-sm text-gray-600">{service.description}</p>
+			<div class="mt-2 flex items-center space-x-4 text-sm text-gray-500">
+				<span>{service.duration_minutes} mins</span>
+				<span>£{service.price}</span>
+			</div>
+		</div>
+		<div
+			class="ml-3 flex h-5 w-5 items-center justify-center rounded border-2 {selected
+				? 'border-primary bg-primary'
+				: 'border-gray-300'}"
+			aria-hidden="true"
+		>
+			{#if selected}
+				<svg class="h-3 w-3 text-white" fill="currentColor" viewBox="0 0 20 20">
+					<path
+						fill-rule="evenodd"
+						d="M16.707 5.293a1 1 0 010 1.414l-8 8a1 1 0 01-1.414 0l-4-4a1 1 0 011.414-1.414L8 12.586l7.293-7.293a1 1 0 011.414 0z"
+						clip-rule="evenodd"
+					></path>
+				</svg>
+			{/if}
+		</div>
+	</div>
+</button>