feat: org-scoped appointments backend, wire appointments page

Add the appointments table, validation, service and CRUD routes
(/api/appointments, RBAC-gated) and the matching frontend data module.
The appointments page now loads and persists real data; KPIs are computed
from it and the schedule/calendar anchor to the real current date.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/types/appointment.ts

@@ -0,0 +1,22 @@
+// The canonical Appointment shape returned by the API. Mirrors the frontend
+// `lib/appointments.ts` Appointment type. Patient fields are denormalized for
+// display; `fileNumber` links back to a patient record when set.
+export type AppointmentStatus =
+  | "confirmed"
+  | "checked-in"
+  | "completed"
+  | "cancelled";
+
+export type Appointment = {
+  id: string;
+  fileNumber: string;
+  name: string;
+  initials: string;
+  date: string; // ISO YYYY-MM-DD
+  time: string; // HH:mm
+  type: string;
+  provider: string;
+  status: AppointmentStatus;
+  createdAt: string;
+  updatedAt: string;
+};