feat: AI-added records save with placeholders + "Added by AI" provenance

Stop blocking AI imports/proposals on missing non-critical fields. Records
the chat agent drafts now save with safe placeholders, auto-generated file
numbers, and a source="ai" marker that surfaces an "Added by AI" badge so a
clinician can review/edit them later.

Backend:
- add `source` (manual|ai) column to patients/appointments/prescriptions
  (migration 0014) + canonical types, services, validation schemas
- relax patient/appointment validation: empty file number allowed, demographic
  + type/provider/initials fall back to placeholders (initials derived from name)
- patients.generateFileNumber() auto-assigns an MRN when one is missing
- proposeAppointment accepts a name when no file number resolves; AI commits +
  /api/ai/import stamp source="ai"

Frontend:
- `source` on Appointment/Patient/Prescription types; AI commits send source="ai"
- reusable <AiBadge> shown on the Patients table/detail and prescriptions list

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

package.json

@@ -1,5 +1,5 @@
 {
   "devDependencies": {
-    "shadcn": "^4.8.3"
+    "shadcn": "^4.11.0"
   }
 }