load models from disk and set a ttl and etag (#7722)

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codex-rs/core/tests/common/responses.rs

@@ -677,7 +677,14 @@ pub async fn start_mock_server() -> MockServer {
         .await;
 
     // Provide a default `/models` response so tests remain hermetic when the client queries it.
-    let _ = mount_models_once(&server, ModelsResponse { models: Vec::new() }).await;
+    let _ = mount_models_once(
+        &server,
+        ModelsResponse {
+            models: Vec::new(),
+            etag: String::new(),
+        },
+    )
+    .await;
 
     server
 }