chore: clean imports and restore test coverage

src/voice_assistant/__init__.py

@@ -1,2 +1,7 @@
-def main() -> None:
-    print("Hello from voice-assistant!")
+"""
+Voice Assistant package.
+
+Provides realtime voice processing components, including
+audio transport, speech recognition, agent orchestration,
+speech synthesis, and turn lifecycle management.
+"""

src/voice_assistant/audio_gateway/app/main.py

@@ -36,7 +36,6 @@ import json
 import logging
 from fastapi import FastAPI, WebSocket, WebSocketDisconnect
 from pydantic import BaseModel, ValidationError
-import os
 
 import asyncio
 
@@ -45,7 +44,6 @@ from voice_assistant.stt.adapter import STTAdapter
 from voice_assistant.tts.adapter import TTSAdapter
 from voice_assistant.turn_manager import (
     TurnManager,
-    TurnState,
 )
 from voice_assistant.agent.adapter import AgentAdapter
 
@@ -72,7 +70,6 @@ from voice_assistant.audio_gateway.app.protocol import (
     AUDIO_SAMPLE_RATE,
     AUDIO_CHANNELS,
     AudioChunk,
-    AudioStart,
     AudioStop,
     Interrupt,
     SessionEnd,

src/voice_assistant/providers.py

@@ -44,7 +44,6 @@ from voice_assistant.config.models import (
 from voice_assistant.stt.adapter import STTAdapter
 from voice_assistant.tts.adapter import TTSAdapter
 
-from voice_assistant.audio.models import CANONICAL_AUDIO_FORMAT
 
 PROVIDER_CONTRACTS: dict[str, type] = {
     "stt": STTAdapter,