Подчистил архитектуру приложения v1 работает

src/app/modules/api/application/stream_service.py

@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from app.core.exceptions import AppError
+from app.modules.api.infrastructure.streaming.sse_encoder import SseEncoder
+from app.modules.api.infrastructure.streaming.sse_event_channel import SseEventChannel
+from app.schemas.common import ModuleName
+
+
+class StreamService:
+    def __init__(self, channel: SseEventChannel, request_exists, encoder: SseEncoder | None = None) -> None:
+        self._channel = channel
+        self._request_exists = request_exists
+        self._encoder = encoder or SseEncoder()
+
+    async def subscribe(self, request_id: str):
+        if not self._request_exists(request_id):
+            raise AppError("request_not_found", f"Agent request not found: {request_id}", ModuleName.BACKEND)
+        return await self._channel.subscribe(request_id, replay=True)
+
+    async def unsubscribe(self, request_id: str, queue) -> None:
+        await self._channel.unsubscribe(request_id, queue)
+
+    def encode(self, event) -> str:
+        return self._encoder.encode(event)