feat: HL7/FHIR, e-prescribing & insurance claims integrations

Real, standards-compliant integration clients that the clinic points at
its own (sandbox or production) endpoints — no mock data.

backend:
- `integrations` table (per org+type) storing endpoint + encrypted
  credentials (reusing the AI-key crypto) + status; Drizzle migration
- services/integrations:
  - fhir.ts — FHIR R4 REST client (pull lab Observations → patient
    record), HL7 v2 ORU parsing, capability-statement connection test
  - eprescribe.ts — NCPDP SCRIPT NewRx message build + transmit
  - claims.ts — X12 837P claim generation + 835 remittance parsing
- `/api/integrations` route: config GET/PUT (owner/admin), connection
  test, and the FHIR sync / HL7 ingest / e-Rx send / claim submit actions,
  RBAC-gated (lab/patient, prescription, invoice)

frontend:
- lib/integrations.ts client
- Settings → Integrations tab to configure endpoints/credentials/enable
  + test each integration
- on-page actions, shown only when the integration is enabled:
  Lab page → FHIR "Sync results" card; prescription sheet → "Send to
  pharmacy"; invoice sheet → "Submit claim"

Production e-Rx/claims routing requires the clinic's own Surescripts /
clearinghouse credentials; the code transmits real messages once supplied.

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

backend/drizzle/meta/_journal.json

@@ -155,6 +155,13 @@
       "when": 1781801972208,
       "tag": "0021_milky_blur",
       "breakpoints": true
+    },
+    {
+      "idx": 22,
+      "version": "7",
+      "when": 1781802557475,
+      "tag": "0022_damp_synch",
+      "breakpoints": true
     }
   ]
 }