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>

frontend/components/settings/settings-view.tsx

@@ -8,6 +8,7 @@ import { AIPanel } from "@/components/settings/settings-ai";
 import { SigningPanel } from "@/components/settings/settings-billing";
 import { CareTeamPanel } from "@/components/settings/settings-care-team";
 import { DevelopersPanel } from "@/components/settings/settings-developers";
+import { IntegrationsPanel } from "@/components/settings/settings-integrations";
 import { ProfilePanel } from "@/components/settings/settings-preferences";
 import { RecordsPanel } from "@/components/settings/settings-records";
 import { useActiveRole } from "@/lib/roles";
@@ -18,6 +19,7 @@ const TABS = [
   { id: "records", labelKey: "settings.tabs.records" },
   { id: "signing", labelKey: "settings.tabs.signing" },
   { id: "careTeam", labelKey: "settings.tabs.careTeam" },
+  { id: "integrations", labelKey: "settings.tabs.integrations" },
   { id: "developers", labelKey: "settings.tabs.developers" },
 ] as const;
 
@@ -70,6 +72,7 @@ export function SettingsView() {
         {activeTab === "records" && <RecordsPanel />}
         {activeTab === "signing" && <SigningPanel />}
         {activeTab === "careTeam" && <CareTeamPanel />}
+        {activeTab === "integrations" && <IntegrationsPanel />}
         {activeTab === "developers" && <DevelopersPanel />}
       </div>
     </div>