feat: Token-basierte Kunden-Statusseite

- Neue /booking/{token} Route für einheitliche Buchungsübersicht
- Vollständige Termin-Details mit Status-Badges (pending/confirmed/cancelled/completed)
- Integrierte Stornierungsfunktion mit Bestätigungsdialog
- Anzeige von Behandlungsdetails, Kundendaten und verbleibender Zeit
- Automatische Berechnung ob Stornierung noch möglich
- Responsive UI mit modernem Design

Server-Erweiterungen:
- BookingAccessToken statt CancellationToken (semantisch präziser)
- Erweiterte Rückgabe von getBookingByToken (Preis, Dauer, canCancel, hoursUntilAppointment)
- Token-Generierung bei Buchungserstellung (pending) und Bestätigung

E-Mail-Integration:
- Status-Links in pending-Mails
- 'Termin verwalten' statt 'Termin stornieren' in confirmed-Mails
- Einheitliches Branding (Pink/Orange statt Rot)

Aufgeräumt:
- Legacy cancellation-page.tsx entfernt
- /cancel/ Route entfernt (keine Rückwärtskompatibilität nötig)
- Backlog aktualisiert

src/server/rpc/cancellation.ts

@@ -4,18 +4,21 @@ import { createKV } from "@/server/lib/create-kv";
 import { createKV as createAvailabilityKV } from "@/server/lib/create-kv";
 import { randomUUID } from "crypto";
 
-// Schema for cancellation token
-const CancellationTokenSchema = z.object({
+// Schema for booking access token (used for both status viewing and cancellation)
+const BookingAccessTokenSchema = z.object({
   id: z.string(),
   bookingId: z.string(),
   token: z.string(),
   expiresAt: z.string(),
   createdAt: z.string(),
+  purpose: z.enum(["booking_access"]), // For future extensibility
 });
 
-type CancellationToken = z.output<typeof CancellationTokenSchema>;
+type BookingAccessToken = z.output<typeof BookingAccessTokenSchema>;
+// Backwards compatibility alias
+type CancellationToken = BookingAccessToken;
 
-const cancellationKV = createKV<CancellationToken>("cancellation_tokens");
+const cancellationKV = createKV<BookingAccessToken>("cancellation_tokens");
 
 // Types for booking and availability
 type Booking = {
@@ -70,12 +73,13 @@ const createToken = os
     expiresAt.setDate(expiresAt.getDate() + 30);
     
     const token = randomUUID();
-    const cancellationToken: CancellationToken = {
+    const cancellationToken: BookingAccessToken = {
       id: randomUUID(),
       bookingId: input.bookingId,
       token,
       expiresAt: expiresAt.toISOString(),
       createdAt: new Date().toISOString(),
+      purpose: "booking_access",
     };
     
     await cancellationKV.setItem(cancellationToken.id, cancellationToken);
@@ -105,15 +109,32 @@ const getBookingByToken = os
     const treatmentsKV = createKV<any>("treatments");
     const treatment = await treatmentsKV.getItem(booking.treatmentId);
     
+    // Calculate if cancellation is still possible
+    const minStornoTimespan = parseInt(process.env.MIN_STORNO_TIMESPAN || "24");
+    const appointmentDateTime = new Date(`${booking.appointmentDate}T${booking.appointmentTime}:00`);
+    const now = new Date();
+    const timeDifferenceHours = (appointmentDateTime.getTime() - now.getTime()) / (1000 * 60 * 60);
+    const canCancel = timeDifferenceHours >= minStornoTimespan && 
+                      booking.status !== "cancelled" && 
+                      booking.status !== "completed";
+    
     return {
       id: booking.id,
       customerName: booking.customerName,
+      customerEmail: booking.customerEmail,
+      customerPhone: booking.customerPhone,
       appointmentDate: booking.appointmentDate,
       appointmentTime: booking.appointmentTime,
       treatmentId: booking.treatmentId,
       treatmentName: treatment?.name || "Unbekannte Behandlung",
+      treatmentDuration: treatment?.duration || 60,
+      treatmentPrice: treatment?.price || 0,
       status: booking.status,
+      notes: booking.notes,
       formattedDate: formatDateGerman(booking.appointmentDate),
+      createdAt: booking.createdAt,
+      canCancel,
+      hoursUntilAppointment: Math.max(0, Math.round(timeDifferenceHours)),
     };
   });