feat: update AI voice settings for improved responsiveness and pacing

tests/test_ai_voice_media_runtime.py

@@ -2861,7 +2861,6 @@ def test_media_runtime_no_speech_watchdog_reprompts_on_silence_timeout():
         handle_media_error=lambda session_id, message, metadata: None,
     )
     runtime._no_speech_reprompt_seconds = 0.05
-    runtime._no_speech_reprompt_poll_seconds = 0.02
 
     spoken: list[str] = []
 
@@ -2887,16 +2886,21 @@ def test_media_runtime_no_speech_watchdog_reprompts_on_silence_timeout():
             frame_ms=20,
             frame_bytes=320,
         )
+        # The no-speech watchdog check now rides the existing keepalive loop
+        # instead of its own dedicated task; keep last_outbound_audio_monotonic
+        # fresh so the loop's silence-keepalive-audio branch (which needs a
+        # real writer) doesn't fire during this test.
+        actor.last_outbound_audio_monotonic = time.monotonic()
         await runtime._set_actor_state(actor, "listening")
-        watchdog_task = asyncio.create_task(runtime._no_speech_reprompt_loop(actor))
-        for _ in range(50):
+        keepalive_task = asyncio.create_task(runtime._keepalive_loop(actor))
+        for _ in range(20):
             if spoken:
                 break
-            await asyncio.sleep(0.02)
+            await asyncio.sleep(0.05)
         actor.closed = True
-        watchdog_task.cancel()
+        keepalive_task.cancel()
         with contextlib.suppress(asyncio.CancelledError, Exception):
-            await watchdog_task
+            await keepalive_task
         assert spoken, "watchdog should reprompt after prolonged silence in listening state"
 
     asyncio.run(_scenario())