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/ai/confirmationSms.ts

@@ -1,6 +1,6 @@
-import twilio from "twilio";
 import { prisma as db } from "@repo/db/client";
 import { storage } from "../storage";
+import { sendTelnyxSms } from "../comms/telnyx-client";
 
 const CONFIRMATION_FALLBACKS: Record<string, (dateLabel: string, time: string) => string> = {
   English:          (d, t) => `Confirmed! Your appointment is on ${d} at ${t}. We look forward to seeing you.`,
@@ -27,20 +27,22 @@ export async function sendAppointmentConfirmationSms(
   lang: string,
 ): Promise<void> {
   try {
-    const [twilioSettings, patient] = await Promise.all([
-      storage.getTwilioSettings(userId),
+    const [telnyxSettings, patient] = await Promise.all([
+      storage.getTelnyxSettings(userId),
       db.patient.findUnique({ where: { id: patientId }, select: { phone: true } }),
     ]);
-    if (!twilioSettings || !patient?.phone) return;
+    if (!telnyxSettings || !patient?.phone) return;
 
     const build = CONFIRMATION_FALLBACKS[lang] ?? CONFIRMATION_FALLBACKS["English"]!;
     const body  = build(dateLabel, time);
 
-    const client = twilio(twilioSettings.accountSid, twilioSettings.authToken);
-    await client.messages.create({ body, from: twilioSettings.phoneNumber, to: patient.phone });
+    await sendTelnyxSms({
+      apiKey: telnyxSettings.apiKey, from: telnyxSettings.phoneNumber, to: patient.phone, text: body,
+      messagingProfileId: telnyxSettings.messagingProfileId,
+    });
 
     await storage.createCommunication({
-      patientId, userId, channel: "sms", direction: "outbound", status: "sent", body,
+      patientId, userId, channel: "sms", direction: "outbound", status: "sent", body, provider: "telnyx",
     });
   } catch {
     // Silent — don't crash the booking flow over a notification failure

apps/Backend/src/ai/patient-conversation-router.ts

@@ -1,6 +1,6 @@
-import twilio from "twilio";
 import { prisma as db } from "@repo/db/client";
 import { storage } from "../storage";
+import { sendTelnyxSms } from "../comms/telnyx-client";
 import { runReminderGraph } from "./reminder-graph";
 import { runRecallGraph, runRecallBookingStep, hasDateOrTimeSignal } from "./recall-graph";
 import { runNewPatientStep } from "./new-patient-graph";
@@ -62,7 +62,7 @@ export function applyOfficeName(template: string, name: string): string {
 /** Save an outbound SMS message (always sms channel — used for async follow-ups). */
 async function saveOutboundSms(patientId: number, body: string): Promise<void> {
   await storage.createCommunication({
-    patientId, channel: "sms", direction: "outbound", status: "sent", body,
+    patientId, channel: "sms", direction: "outbound", status: "sent", body, provider: "telnyx",
   });
 }
 
@@ -132,8 +132,8 @@ async function runMassHealthCheckAndNotify(
     const credentials = await storage.getInsuranceCredentialByUserAndSiteKey(patient.userId, "MH");
     if (!credentials) return;
 
-    const twilioSettings = await storage.getTwilioSettings(patient.userId);
-    if (!twilioSettings || !patient.phone) return;
+    const telnyxSettings = await storage.getTelnyxSettings(patient.userId);
+    if (!telnyxSettings || !patient.phone) return;
 
     await runEligibilityProcessor({
       userId: patient.userId,
@@ -198,11 +198,12 @@ async function runMassHealthCheckAndNotify(
         ? "asked_self_pay"
         : "asked_other_insurance_after_inactive";
 
-    const client = twilio(twilioSettings.accountSid, twilioSettings.authToken);
-    await client.messages.create({
-      body:  resultText,
-      from:  twilioSettings.phoneNumber,
-      to:    patient.phone,
+    await sendTelnyxSms({
+      apiKey: telnyxSettings.apiKey,
+      from:   telnyxSettings.phoneNumber,
+      to:     patient.phone,
+      text:   resultText,
+      messagingProfileId: telnyxSettings.messagingProfileId,
     });
 
     await saveOutboundSms(patient.id, resultText);