voice-call: log assistant speech as bot transcript in realtime calls

call.speaking events already carry a text field (used by Telnyx) but the
manager was discarding it. Wire it through addTranscriptEntry so any
call.speaking event with non-empty text records a speaker:"bot" entry.

In the realtime handler, emit call.speaking for assistant turns when the
transcript is final, mirroring the existing user call.speech path. This
restores speaker:"bot" entries in calls.jsonl for realtime calls.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

extensions/voice-call/src/manager/events.ts

@@ -204,6 +204,9 @@ export function processEvent(ctx: EventContext, event: NormalizedEvent): void {
       break;
 
     case "call.speaking":
+      if (event.text) {
+        addTranscriptEntry(call, "bot", event.text);
+      }
       transitionState(call, "speaking");
       break;
 

extensions/voice-call/src/webhook/realtime-handler.ts

@@ -233,7 +233,6 @@ export class RealtimeCallHandler {
 
       onTranscript: (role, text, isFinal) => {
         if (isFinal) {
-          // Emit user speech through the manager for transcript persistence
           if (role === "user") {
             const event: NormalizedEvent = {
               id: `realtime-speech-${callSid}-${Date.now()}`,
@@ -245,6 +244,17 @@ export class RealtimeCallHandler {
               isFinal: true,
             };
             this.manager.processEvent(event);
+          } else if (role === "assistant") {
+            // Log assistant turns via call.speaking so they appear as speaker:"bot"
+            // in the transcript (same mechanism Telnyx uses for TTS speech).
+            this.manager.processEvent({
+              id: `realtime-bot-${callSid}-${Date.now()}`,
+              type: "call.speaking",
+              callId,
+              providerCallId: callSid,
+              timestamp: Date.now(),
+              text,
+            });
           }
         }
       },