feat: label AI-rescheduled appointments and add manual confirm option

- Add movedByAi boolean column to Appointment table (default false)
- reschedule-graph: set movedByAi=true when AI moves an appointment
- PATCH /api/appointments/:id/confirm endpoint clears the movedByAi flag
- Schedule grid: show teal AI badge on appointment cards where movedByAi=true
- Right-click context menu: 'Manually Confirmed' removes the AI badge via the confirm endpoint

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

packages/db/generated/prisma/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "prisma-client-841b8b7214f98d624249fcce8221ef527e6df11b7ccf3685b686d6606451965c",
+  "name": "prisma-client-bdc07eb887b3bb595b0151af876608d0c2dad5b625bc466303ffa3819c38e3ca",
   "main": "index.js",
   "types": "index.d.ts",
   "browser": "default.js",