Add voice analytics filters and metrics

backend/app/api/voice_sessions.py

@@ -116,11 +116,21 @@ async def get_latest_active_voice_session(
 @router.get("/voice-sessions/analytics", response_model=VoiceSessionAnalyticsResponse)
 async def get_voice_session_analytics(
     days: int | None = Query(default=30, ge=1, le=365),
+    provider: str | None = Query(default=None, min_length=1, max_length=64),
+    session_status: (
+        Literal["draft", "active", "waiting_user", "completed", "abandoned"] | None
+    ) = Query(default=None),
     user: User = Depends(require_user),
     db: AsyncSession = Depends(get_db),
 ):
     """Get aggregate voice co-creation analytics for the current user."""
-    return await get_voice_session_analytics_service(user.id, db, days=days)
+    return await get_voice_session_analytics_service(
+        user.id,
+        db,
+        days=days,
+        provider=provider,
+        session_status=session_status,
+    )
 
 
 @router.get("/voice-sessions/{session_id}", response_model=VoiceSessionDetailResponse)