Keep the path attributes of rejected routes, and show them

A rejected route was recorded with its prefix, reason and AS path, which
is not enough to tell why a neighbor sent it: whether a /32 is a
blackhole request, which communities a leaked route carries, which
network marked it Only to Customer.

Each recorded rejection now keeps the attributes of the UPDATE it came
in, without the NLRI of MP_REACH_NLRI and MP_UNREACH_NLRI, and its next
hop. The attributes are copied once per UPDATE, only when a route of it
is rejected, and shared by its rejected routes. A route rejected later,
when the RPKI data changes, has the attributes it was stored with.

/api/routes/rejected gives them as `summary` and `attributes`, as for
received routes, and the status page shows them under "show" in each
row of the refused routes.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/integration-tests/tests/debugging.rs

@@ -250,6 +250,20 @@ async fn test_refused_routes_can_be_seen_and_counted() -> Result<()> {
             row("10.0.0.0/8", "bogon prefix", "[3333]"),
         ]
     );
+    // And with all its attributes, as for a route that was taken, to see
+    // what came along with it.
+    let latest = &record["recent"][0];
+    assert_eq!(latest["summary"]["next_hop"], "192.0.2.1");
+    assert_eq!(latest["summary"]["origin"], "IGP");
+    assert_eq!(
+        latest["summary"]["as_path"],
+        serde_json::json!([3333, 2121])
+    );
+    assert_eq!(
+        latest["attributes"].as_array().map(Vec::len),
+        Some(3),
+        "ORIGIN, AS_PATH and NEXT_HOP: {latest}"
+    );
     // Asked for by peer, by name or by address.
     for peer in ["refused-demo", "127.0.0.1"] {
         let one: Value = get(&format!("/api/routes/rejected?peer={peer}"))