feat: migrate SMS/voice to Telnyx (TeXML), keep browser dial pad on Twilio

Twilio now handles only the in-browser dial pad (Access Token + browser-Device
outbound TwiML); Telnyx takes over SMS, inbound voicemail, the AI voice
conversation loop, and staff-triggered outbound calls via TeXML. Adds
TelnyxSettings model, Communication.provider discriminator, new comms/routes
modules, and a real Telnyx Settings page.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/Backend/src/storage/index.ts

@@ -18,6 +18,7 @@ import { patientDocumentsStorage } from './patientDocuments-storage';
 import * as exportPaymentsReportsStorage from "./export-payments-reports-storage";
 import { cronJobLogStorage } from "./cron-job-log-storage";
 import { twilioStorage } from "./twilio-storage";
+import { telnyxStorage } from "./telnyx-storage";
 import { aiSettingsStorage } from "./ai-settings-storage";
 import { officeHoursStorage } from "./office-hours-storage";
 import { officeContactStorage } from "./office-contact-storage";
@@ -47,6 +48,7 @@ export const storage = {
   ...exportPaymentsReportsStorage,
   ...cronJobLogStorage,
   ...twilioStorage,
+  ...telnyxStorage,
   ...aiSettingsStorage,
   ...officeHoursStorage,
   ...officeContactStorage,

apps/Backend/src/storage/telnyx-storage.ts

@@ -0,0 +1,25 @@
+import { prisma as db } from "@repo/db/client";
+
+export type TelnyxSettingsData = {
+  apiKey: string;
+  accountSid?: string | null;
+  phoneNumber: string;
+  texmlApplicationId?: string | null;
+  messagingProfileId?: string | null;
+  webhookPublicKey?: string | null;
+  greetingMessage?: string | null;
+};
+
+export const telnyxStorage = {
+  async getTelnyxSettings(userId: number) {
+    return db.telnyxSettings.findUnique({ where: { userId } });
+  },
+
+  async upsertTelnyxSettings(userId: number, data: TelnyxSettingsData) {
+    return db.telnyxSettings.upsert({
+      where: { userId },
+      update: data,
+      create: { userId, ...data },
+    });
+  },
+};

apps/Backend/src/storage/twilio-storage.ts

@@ -24,6 +24,9 @@ export type CommunicationCreateData = {
   body?: string;
   callDuration?: number;
   twilioSid?: string;
+  // Which platform produced twilioSid — defaults to "twilio" (dial-pad calls) when
+  // omitted; Telnyx call sites (everything else) pass "telnyx" explicitly.
+  provider?: "twilio" | "telnyx";
 };
 
 export const twilioStorage = {