chore: 添加虚拟环境到仓库

- 添加 backend_service/venv 虚拟环境
- 包含所有Python依赖包
- 注意：虚拟环境约393MB，包含12655个文件

backend_service/venv/lib/python3.13/site-packages/chromadb/test/stress/test_many_collections.py

@@ -0,0 +1,37 @@
+from typing import List
+import numpy as np
+
+from chromadb.api import ServerAPI
+from chromadb.api.models.Collection import Collection
+
+
+def test_many_collections(client: ServerAPI) -> None:
+    """Test that we can create a large number of collections and that the system
+    # remains responsive."""
+    client.reset()
+
+    N = 10
+    D = 10
+
+    metadata = None
+    if client.get_settings().is_persistent:
+        metadata = {"hnsw:batch_size": 3, "hnsw:sync_threshold": 3}
+    else:
+        # We only want to test persistent configurations in this way, since the main
+        # point is to test the file handle limit
+        return
+
+    num_collections = 10000
+    collections: List[Collection] = []
+    for i in range(num_collections):
+        new_collection = client.create_collection(
+            f"test_collection_{i}",
+            metadata=metadata,
+        )
+        collections.append(new_collection)
+
+    # Add a few embeddings to each collection
+    data = np.random.rand(N, D).tolist()
+    ids = [f"test_id_{i}" for i in range(N)]
+    for i in range(num_collections):
+        collections[i].add(ids, data)