feat(bookings): dashboard cancellation and waitlist promotion

- POST /v1/catalog/bookings/{id}/cancel lets businesses cancel
  tenant-owned bookings; two-step confirm in the detail modal
- Shared PromoteWaitlist helper promotes earliest waitlisted bookings
  when a class seat frees, on both dashboard and customer cancel paths;
  promoted customers get a confirmation email, waitlist ledger marked
  resolved
- waitlisted status surfaced in bookings UI: stats card, filter, warning
  badge, demo seed, CS+EN strings
- BookingRecord gains created_at for fair ordering; GetBookingByID and
  ResolveWaitlistEntry added to the repository surface

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

packages/api-client/src/generated/types.ts

@@ -287,6 +287,22 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/v1/catalog/bookings/{bookingID}/cancel": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        get?: never;
+        put?: never;
+        post: operations["cancelDashboardBooking"];
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/v1/catalog/class-sessions": {
         parameters: {
             query?: never;
@@ -2030,6 +2046,40 @@ export interface operations {
             };
         };
     };
+    cancelDashboardBooking: {
+        parameters: {
+            query?: never;
+            header?: never;
+            path: {
+                bookingID: string;
+            };
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description Booking cancelled; freed class seats promote the waitlist */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content?: never;
+            };
+            /** @description Booking already cancelled */
+            400: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content?: never;
+            };
+            /** @description Booking not found */
+            404: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content?: never;
+            };
+        };
+    };
     listClassSessions: {
         parameters: {
             query?: never;