[Communication][High] Reject or implement IP-authenticated and mutual-TLS SIP accounts #111

Severity

High

Problem

The admin UI and API advertise and persist Digest, IP-authenticated and mutual-TLS SIP accounts. The SDK adapter explicitly throws for every method except Digest. Unsupported records are accepted and later skipped by startup provisioning while the UI can remain on Connecting.

Evidence

• custom/static-plugins/Communication/src/Infrastructure/Voice/SdkSipAccountFactory.cs:48
• custom/static-plugins/Communication/app/admin/src/CommunicationAdminPage.vue:12

Acceptance criteria

Choose and document one path:

• Implement IP authentication and mutual TLS with production interop tests; or
• remove/hide unsupported methods and reject them with a clear 422 validation response.

Additionally:

• Existing unsupported records migrate or surface an actionable error.
• Secrets/certificates follow the repository credential-protection model.
• UI and API expose exactly the capabilities supported by the selected provider.