hive-agent: surface an interrupted-turn banner in the wake prompt after /cancel

hive-agent/src/web_ui/actions.rs

@@ -54,7 +54,17 @@ pub(super) async fn post_send(
 pub(super) async fn post_cancel_turn(State(state): State<AppState>) -> Response {
     let out = super::sigint_claude().await;
     let note = match out {
-        Ok(o) if o.status.success() => "operator: /cancel — sent SIGINT to claude".to_owned(),
+        Ok(o) if o.status.success() => {
+            // A process actually got signalled — the *next* turn's wake
+            // prompt should tell the agent it was cut off mid-work. Only
+            // set on an actual signal: a `pkill` exit 1 ("no process to
+            // interrupt") means /cancel raced an already-finished turn, so
+            // there's nothing to flag as interrupted.
+            state
+                .interrupted
+                .store(true, std::sync::atomic::Ordering::Relaxed);
+            "operator: /cancel — sent SIGINT to claude".to_owned()
+        }
         Ok(o) if o.status.code() == Some(1) => {
             "operator: /cancel — no claude process to interrupt".to_owned()
         }

hive-agent/src/web_ui/mod.rs

@@ -19,6 +19,7 @@ mod stream;
 
 use std::net::SocketAddr;
 use std::path::{Path, PathBuf};
+use std::sync::atomic::AtomicBool;
 use std::sync::{Arc, Mutex};
 
 use anyhow::{Context, Result};
@@ -57,6 +58,13 @@ struct AppState {
     /// VNC port from the `HIVE_GUI_VNC_PORT` env var at startup.
     /// `None` when unset (gui not enabled for this agent).
     gui_vnc_port: Option<u16>,
+    /// Set by `post_cancel_turn` on a successful SIGINT; read-and-cleared
+    /// by the serve loop's next `handle_turn` to prepend
+    /// `hive_sh4re::INTERRUPTED_HINT` to that turn's wake prompt. Shared
+    /// with the serve loop via the same `Arc` (see `serve_main`) — an
+    /// in-memory flag, not a marker file, since a `/cancel` from a prior
+    /// process lifetime isn't meaningful once the harness restarts.
+    interrupted: Arc<AtomicBool>,
 }
 
 /// Bind the per-container web listener and serve the SPA.
@@ -77,6 +85,7 @@ pub async fn serve(
     login: LoginStateCell,
     bus: Bus,
     socket: PathBuf,
+    interrupted: Arc<AtomicBool>,
 ) -> Result<()> {
     let gui_vnc_port = read_gui_vnc_port();
     let static_dir: PathBuf = std::env::var_os("HIVE_STATIC_DIR")
@@ -99,6 +108,7 @@ pub async fn serve(
         bus,
         socket,
         gui_vnc_port,
+        interrupted,
     };
     let app: Router<AppState> = Router::new()
         .route("/api/state", get(state::api_state))