feat: add customer-facing appointment notes (GRO-106)

- Migration 0014: add customer_notes column to appointments
- Schema update: add customerNotes field to appointments table
- Factory update: include customerNotes in buildAppointment
- Portal route: PATCH /api/portal/appointments/:id/notes
  - Ownership validation via impersonation session
  - Future-only validation (no edits after start)
  - 500 character limit
- Register portal router in index.ts

Co-Authored-By: Paperclip <noreply@paperclip.ing>

packages/db/migrations/0014_customer_notes.sql

@@ -0,0 +1,3 @@
+ALTER TABLE appointments ADD COLUMN customer_notes TEXT;
+
+CREATE INDEX idx_appointments_customer_notes ON appointments (client_id) WHERE customer_notes IS NOT NULL;

packages/db/src/factories.ts

@@ -140,6 +140,7 @@ export function buildAppointment(
     confirmedAt: null,
     cancelledAt: null,
     confirmationToken: null,
+    customerNotes: null,
     createdAt: new Date("2025-01-01T00:00:00Z"),
     updatedAt: new Date("2025-01-01T00:00:00Z"),
   };

packages/db/src/schema.ts

@@ -169,6 +169,8 @@ export const appointments = pgTable("appointments", {
   cancelledAt: timestamp("cancelled_at"),
   // Token for tokenized email confirm/cancel links (no auth required)
   confirmationToken: text("confirmation_token").unique(),
+  // Customer-provided note visible to groomer (500 char max, editable until appointment starts)
+  customerNotes: text("customer_notes"),
   createdAt: timestamp("created_at").notNull().defaultNow(),
   updatedAt: timestamp("updated_at").notNull().defaultNow(),
 });