feat: add client disable/deletion with soft-delete (#67)

Add soft-delete support for clients: disable is the default action
(hiding from client list and booking flow), with permanent deletion
requiring explicit type-to-confirm. Disabled clients remain in
reporting and can be re-enabled by staff.

- Add client_status enum (active/disabled) and disabled_at column
- API defaults GET /api/clients to active-only, ?includeDisabled=true shows all
- PATCH /api/clients/:id accepts status field for disable/enable
- DELETE requires ?confirm=true query param
- Booking flow skips disabled clients
- Frontend: show disabled toggle, disable/enable buttons, delete confirmation modal

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/types/src/index.ts

@@ -8,6 +8,8 @@ export type AppointmentStatus =
   | "cancelled"
   | "no_show";
 
+export type ClientStatus = "active" | "disabled";
+
 export interface Client {
   id: string;
   name: string;
@@ -16,6 +18,8 @@ export interface Client {
   address: string | null;
   notes: string | null;
   emailOptOut: boolean;
+  status: ClientStatus;
+  disabledAt: string | null;
   createdAt: string;
   updatedAt: string;
 }