feat(server): 暴露 /api/sessions/{sid}/ws 进度流端点（+websockets 依赖）

tests/test_progress_ws.py

@@ -0,0 +1,24 @@
+import threading
+from fastapi.testclient import TestClient
+from genesis.server.app import create_app
+from genesis.server.hub import hub
+from genesis.server.store import SessionStore
+
+
+def _client(tmp_path):
+    return TestClient(create_app(
+        store=SessionStore(db_path=str(tmp_path / "s.db")),
+        data_root=str(tmp_path / "data"), engine="fake"))
+
+
+def test_ws_streams_progress(tmp_path):
+    c = _client(tmp_path)
+
+    def trigger():
+        hub.emit("ws-s1", {"type": "progress", "step": "gen", "status": "ok", "detail": "生成中"})
+
+    with c.websocket_connect("/api/sessions/ws-s1/ws") as ws:
+        threading.Thread(target=trigger).start()
+        data = ws.receive_json()
+        assert data["type"] == "progress"
+        assert data["step"] == "gen"