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/shared/.prisma-zod-generator-manifest.json

@@ -1,7 +1,7 @@
 {
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   "generatorVersion": "1.0.0",
-  "generatedAt": "2026-05-08T23:38:39.880Z",
+  "generatedAt": "2026-05-11T21:48:22.459Z",
   "outputPath": "/home/ee/Desktop/DentalManagementMH05/packages/db/shared",
   "files": [
     "schemas/enums/TransactionIsolationLevel.schema.ts",