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/proto/utils.py

@@ -0,0 +1,68 @@
+from typing import Optional, Set
+import grpc
+from tenacity import retry, stop_after_attempt, wait_exponential_jitter, retry_if_result
+from opentelemetry.trace import Span
+
+
+class RetryOnRpcErrorClientInterceptor(
+    grpc.UnaryUnaryClientInterceptor, grpc.UnaryStreamClientInterceptor
+):
+    """
+    A gRPC client interceptor that retries RPCs on specific status codes. By default, it retries on UNAVAILABLE and UNKNOWN status codes.
+
+    This interceptor should be placed after the OpenTelemetry interceptor in the interceptor list.
+    """
+
+    max_attempts: int
+    retryable_status_codes: Set[grpc.StatusCode]
+
+    def __init__(
+        self,
+        max_attempts: int = 5,
+        retryable_status_codes: Set[grpc.StatusCode] = set(
+            [grpc.StatusCode.UNAVAILABLE, grpc.StatusCode.UNKNOWN]
+        ),
+    ) -> None:
+        self.max_attempts = max_attempts
+        self.retryable_status_codes = retryable_status_codes
+
+    def _intercept_call(self, continuation, client_call_details, request_or_iterator):
+        sleep_span: Optional[Span] = None
+
+        def before_sleep(_):
+            from chromadb.telemetry.opentelemetry import tracer
+
+            nonlocal sleep_span
+            if tracer is not None:
+                sleep_span = tracer.start_span("Waiting to retry RPC")
+
+        @retry(
+            wait=wait_exponential_jitter(0.1, jitter=0.1),
+            stop=stop_after_attempt(self.max_attempts),
+            retry=retry_if_result(lambda x: x.code() in self.retryable_status_codes),
+            before_sleep=before_sleep,
+        )
+        def wrapped(*args, **kwargs):
+            nonlocal sleep_span
+            if sleep_span is not None:
+                sleep_span.end()
+                sleep_span = None
+            return continuation(*args, **kwargs)
+
+        return wrapped(client_call_details, request_or_iterator)
+
+    def intercept_unary_unary(self, continuation, client_call_details, request):
+        return self._intercept_call(continuation, client_call_details, request)
+
+    def intercept_unary_stream(self, continuation, client_call_details, request):
+        return self._intercept_call(continuation, client_call_details, request)
+
+    def intercept_stream_unary(
+        self, continuation, client_call_details, request_iterator
+    ):
+        return self._intercept_call(continuation, client_call_details, request_iterator)
+
+    def intercept_stream_stream(
+        self, continuation, client_call_details, request_iterator
+    ):
+        return self._intercept_call(continuation, client_call_details, request_iterator)