test: align concurrency fixtures with runtime boundaries

Centralize isolated Redis test connections in the shared test module, use the canonical Claude Messages format, and correct the borrowed entry comparison.

crates/aether-billing/src/event_enrichment.rs

@@ -973,8 +973,8 @@ mod tests {
         let mut event = wire_billing_event("wire-claude-cache");
         event.data.model = "claude-sonnet-4-6".to_string();
         event.data.target_model = Some("claude-sonnet-4-6".to_string());
-        event.data.api_format = Some("claude:chat".to_string());
-        event.data.endpoint_api_format = Some("claude:chat".to_string());
+        event.data.api_format = Some("claude:messages".to_string());
+        event.data.endpoint_api_format = Some("claude:messages".to_string());
         event.data.provider_request_body = None;
         event.data.provider_request_body_state = Some(UsageBodyCaptureState::Disabled);
         event.data.cache_creation_input_tokens = Some(200);

crates/aether-runtime/state/src/lib.rs

@@ -1995,6 +1995,14 @@ mod tests {
     use std::process::{Child, Command, Stdio};
     use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
+    async fn redis_test_connection(url: &str) -> ::redis::aio::MultiplexedConnection {
+        ::redis::Client::open(url)
+            .expect("test Redis client")
+            .get_multiplexed_async_connection()
+            .await
+            .expect("test Redis connection")
+    }
+
     mod stream_receive {
         include!("redis/stream_receive_tests.rs");
     }

crates/aether-runtime/state/src/redis/dead_letter_transfer_tests.rs

@@ -14,11 +14,7 @@ async fn transfer_runtime(
         );
         return None;
     };
-    let mut admin = ::redis::Client::open(server.redis_url.clone())
-        .expect("transfer admin client")
-        .get_multiplexed_async_connection()
-        .await
-        .expect("transfer admin connection");
+    let mut admin = redis_test_connection(&server.redis_url).await;
     ::redis::cmd("ACL")
         .arg("SETUSER")
         .arg(TRANSFER_USER)
@@ -175,7 +171,7 @@ async fn assert_transfer_source_unchanged(
 ) {
     assert_eq!(
         transfer_entries(admin, source).await.as_slice(),
-        std::slice::from_ref(&entry)
+        std::slice::from_ref(entry)
     );
     let pending = transfer_pending(admin, source).await;
     assert_eq!(pending.len(), 1);

crates/aether-runtime/state/src/redis/stream_receive_tests.rs

@@ -28,11 +28,7 @@ async fn receive_runtime(
         );
         return None;
     };
-    let mut admin = ::redis::Client::open(server.redis_url.clone())
-        .expect("test admin client")
-        .get_multiplexed_async_connection()
-        .await
-        .expect("test admin connection");
+    let mut admin = redis_test_connection(&server.redis_url).await;
     ::redis::cmd("ACL")
         .arg("SETUSER")
         .arg("stream-reader")

crates/aether-runtime/state/src/redis/usage_limit_cleanup_tests.rs

@@ -46,11 +46,7 @@ impl Fixture {
             eprintln!("usage cleanup {protocol} skipped: isolated Redis unavailable");
             return None;
         };
-        let mut admin = ::redis::Client::open(server.redis_url.clone())
-            .unwrap()
-            .get_multiplexed_async_connection()
-            .await
-            .unwrap();
+        let mut admin = redis_test_connection(&server.redis_url).await;
         ::redis::cmd("ACL")
             .arg("SETUSER")
             .arg("usage-cleanup")
@@ -1072,14 +1068,11 @@ async fn redis_usage_cleanup_copy_refuses_existing_temporary_and_denied_expirati
         .query_async::<()>(&mut fixture.admin)
         .await
         .unwrap();
-    let mut connection = ::redis::Client::open(format!(
+    let mut connection = redis_test_connection(&format!(
         "redis://usage-cleanup:usage-cleanup-test-password@127.0.0.1:{}/6",
         fixture._server.port,
     ))
-    .unwrap()
-    .get_multiplexed_async_connection()
-    .await
-    .unwrap();
+    .await;
     let script = ::redis::Script::new(include_str!("usage_copy.lua"));
     let result = script
         .key(source)