Class TwilioTelephonyService

Builds the per-session SDK binding that wires the REAL Twilio bindings (REST client + the per-call media registry) onto the telephony driver — overriding the package's default unbound SDK. The SDK is wrapped so the tracker learns of every call end (releasing the max-duration timer).

Cancels every timer and drops tracked state (server shutdown).

Handles Twilio's async answering-machine verdict. A machine or fax hangs the call up unless onMachine is 'continue' (then the verdict is only logged). human/unknown verdicts are ignored.

Admits an INBOUND call: resolves the dialed DID to a pinned agent, registers the call + its media-socket token, and starts the bridge session in the background. Returns as soon as the call is admitted so the voice webhook can answer inside Twilio's short timeout; the Media-Streams socket (and any audio the caller speaks) is buffered until the session is ready. Returns { accepted:false } (never throws) when no agent identity matches the DID, so the webhook can answer with a polite "no agent" message.

Handles a Twilio status-callback event. A terminal status (busy, no-answer, failed, canceled, completed) ends the call's bridge session — an unanswered outbound call never opens a media socket, so without this the session would linger. Non-terminal statuses are ignored.

Places an OUTBOUND call from a given agent identity to a destination number, after the shared outbound gate (agent permission, destination policy, rate limit) has authorized it. The bound RealTwilioBindings.createCall issues the Twilio REST POST /Calls with the <Connect><Stream> TwiML; the returned Call SID is the bridge's external connection id.