feat(core): consolidate auth service into backend and implement stripe billing

This commit performs a major architectural refactor by migrating the standalone `auth-service` into the main `backend` application, enabling a unified codebase and simplified deployment. It also introduces comprehensive Stripe billing support and a new administrative dashboard.

Key changes:
- **Architecture**: Deleted `apps/auth-service` and integrated its functionality (JWT, magic links, OAuth, user management) into `apps/backend`.
- **Billing**: Added Stripe integration to `backend`, supporting both monthly and yearly subscription cycles with automatic plan entitlement enforcement (e.g., location limits).
- **Admin Dashboard**: Implemented a new administrative service and API endpoints to manage tenants, users, and view platform-wide statistics.
- **Frontend**:
    - Added a new pricing page with monthly/yearly toggle and comparison table.
    - Integrated Stripe and Sentry for payments and error tracking.
    - Improved dashboard UX/UI and added i18n support for new features.
    - Enhanced the public booking flow with better validation and contact form integration.
- **Database**: Added migrations for users, magic links, password resets, OAuth states, admin audit logs, and refresh tokens.
- **DevOps**: Updated environment configurations for Railway and Vercel, and streamlined the project's `package.json` scripts.

apps/frontend/src/routes/public-booking-route.tsx

@@ -16,6 +16,8 @@ export function PublicBookingRoute() {
   const [customerName, setCustomerName] = createSignal("");
   const [customerEmail, setCustomerEmail] = createSignal("");
   const [notes, setNotes] = createSignal("");
+  const [highlightContact, setHighlightContact] = createSignal(false);
+  let contactFormRef: HTMLDivElement | undefined;
   const [availability, { refetch }] = createResource(() => {
     const slug = tenantSlug();
     if (!slug) return null;
@@ -31,6 +33,9 @@ export function PublicBookingRoute() {
   const bookSlot = async (slot: components["schemas"]["TimeSlot"]) => {
     if (!customerName().trim() || !customerEmail().trim()) {
       setBookingError(i18n.t("booking.customerRequired"));
+      setHighlightContact(true);
+      contactFormRef?.scrollIntoView({ behavior: "smooth", block: "center" });
+      setTimeout(() => setHighlightContact(false), 2000);
       return;
     }
 
@@ -105,8 +110,8 @@ export function PublicBookingRoute() {
       <Show when={tenantSlug()}>
       <div class="grid gap-8 lg:grid-cols-[1.1fr_0.9fr]">
         {/* Sidebar - Contact form - ORDER 1 on mobile, 2 on desktop */}
-        <div class="space-y-6 order-1 lg:order-2">
-          <Card class="surface-elevated animate-slide-up" style={{ "animation-delay": "0.3s" }}>
+        <div class="space-y-6 order-1 lg:order-2" ref={(el) => { contactFormRef = el; }}>
+          <Card class={`surface-elevated animate-slide-up transition-all duration-300 ${highlightContact() ? 'ring-2 ring-accent shadow-lg' : ''}`} style={{ "animation-delay": "0.3s" }}>
             <CardHeader>
               <CardTitle class="font-display text-xl">{i18n.t("booking.customer.title")}</CardTitle>
               <CardDescription>{i18n.t("booking.customer.body")}</CardDescription>