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>

packages/db/generated/prisma/package.json

@@ -1,5 +1,5 @@
 {
-  "name": "prisma-client-11a124b84a93d3e63379c8a6769ab83d8729151f8cca035589101564f7ede8ed",
+  "name": "prisma-client-85ee1e66f23d650a3f0c01310fbe1ede142a47bab2aa7d55e25b3a29308a8e32",
   "main": "index.js",
   "types": "index.d.ts",
   "browser": "default.js",