ci: add test for pd minifront serving

Already confirmed this test fails on main, which is good, because main
is broken. Let's see if it passes on CI on the PR fixing it...

crates/bin/pd/tests/network_integration.rs

@@ -4,6 +4,8 @@
 //! headers in all contexts. Does NOT evaluate application logic; see the
 //! integration tests for pcli/pclientd for that.
 
+use http::StatusCode;
+
 #[ignore]
 #[tokio::test]
 /// Confirm that permissive CORS headers are returned in HTTP responses
@@ -21,3 +23,19 @@ async fn check_cors_headers() -> anyhow::Result<()> {
     );
     Ok(())
 }
+
+#[ignore]
+#[tokio::test]
+/// Confirm that the a naive GET on the gRPC route returns a 200,
+/// as a sanity check that we haven't badly broken the minifront static asset bundling.
+/// This check does *not* confirm that page works correctly, but it does confirm
+/// it's at least loading, which guards against path regressions in the asset building.
+/// See GH4139 for context.
+async fn check_minifront_http_ok() -> anyhow::Result<()> {
+    let client = reqwest::Client::new();
+    let pd_url =
+        std::env::var("PENUMBRA_NODE_PD_URL").unwrap_or("http://localhost:8080".to_string());
+    let r = client.get(pd_url).send().await?;
+    assert_eq!(r.status(), StatusCode::OK);
+    Ok(())
+}