add sandbox network auto-create and restore dind compose

test/test_create_http.py

@@ -1,6 +1,7 @@
 import asyncio
 import json
 from datetime import UTC, datetime, timedelta
+from typing import Any
 from uuid import UUID
 
 import pytest
@@ -109,10 +110,22 @@ class FakeDockerClient(DockerClient):
         self.base_url = base_url
         self.close_calls = 0
 
+    @property  # type: ignore[override]
+    def networks(self) -> Any:
+        return _FakeNetworks()
+
     def close(self) -> None:
         self.close_calls += 1
 
 
+class _FakeNetworks:
+    def get(self, name: str) -> None:
+        return None
+
+    def create(self, name: str) -> None:
+        return None
+
+
 class EmptySandboxState:
     def __init__(self) -> None:
         self.calls = 0