test(agent): wait for local admission after transfer cancellation

crates/rds-agent/tests/local_sync.rs

@@ -302,17 +302,25 @@ async fn canceled_transfer_releases_its_slot_without_closing_tcp_or_the_session(
             .await
             .unwrap()
             .unwrap();
-        let stats = if upload {
-            client
-                .send_file(session, &destination.join("file"))
-                .await
-                .unwrap()
-        } else {
-            client
-                .recv_file(session, "file", &destination)
-                .await
-                .unwrap()
-        };
+        // Remote RESET observation is not a fence for the local manager's
+        // canceled worker/permit destructor. Require bounded local admission
+        // after cleanup; only TransferBusy is a non-admitted probe. Never
+        // replay an accepted transfer or hide a transport/filesystem failure.
+        let stats = tokio::time::timeout(Duration::from_secs(3), async {
+            loop {
+                let result = if upload {
+                    client.send_file(session, &destination.join("file")).await
+                } else {
+                    client.recv_file(session, "file", &destination).await
+                };
+                match result {
+                    Err(Error::Rejected(ErrorCode::TransferBusy)) => tokio::task::yield_now().await,
+                    result => break result.unwrap(),
+                }
+            }
+        })
+        .await
+        .expect("canceled local transfer did not release admission within its bound");
         assert_eq!(stats.bytes, 18);
         assert_eq!(
             std::fs::read(if upload {

docs/local-sessions.md

@@ -224,7 +224,10 @@ manager session remain usable. Blocking filesystem calls already in progress
 cannot be revoked: cancellation, timeout or a lost reply can leave a completed
 commit. Inspect the destination before retrying; no automatic replay or rollback
 is promised. An immediate retry may encounter the remote service's transient
-busy refusal while cancellation cleanup finishes.
+busy refusal while cancellation cleanup finishes. A remote stream RESET is
+not an acknowledgement that the independent local manager has finished
+dropping its admission permit; cancellation fixtures bound that local release
+without replaying an accepted transfer.
 
 `sync_send` / `sync_recv` operation telemetry records duration and
 `ok` / `error` / `cancelled` outcomes through the existing safe JSON and Vector