mind: use tokio-scoped for Mind/UI loop lifetimes

Both event loops borrow &mind through a scoped spawn — no Arc on
Mind needed. Interior Arcs on agent/shared stay (background spawns
need 'static), but event_loop::run() now takes &Arc refs instead
of cloned Arcs.

Co-Authored-By: Kent Overstreet <kent.overstreet@linux.dev>

Cargo.lock

@@ -2953,6 +2953,7 @@ dependencies = [
  "tiktoken-rs",
  "tokio",
  "tokio-rustls",
+ "tokio-scoped",
  "tokio-util",
  "toml",
  "tracing",
@@ -4371,6 +4372,16 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "tokio-scoped"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e4beb8ba13bc53ac53ce1d52b42f02e5d8060f0f42138862869beb769722b256"
+dependencies = [
+ "tokio",
+ "tokio-stream",
+]
+
 [[package]]
 name = "tokio-stream"
 version = "0.1.18"

Cargo.toml

@@ -65,6 +65,7 @@ webpki-roots = "1"
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 tracing-appender = "0.2"
+tokio-scoped = "0.2.0"
 
 [build-dependencies]
 capnpc = "0.20"

src/user/event_loop.rs

@@ -31,22 +31,28 @@ pub async fn start(cli: crate::user::CliArgs) -> Result<()> {
     let (mind_tx, mind_rx) = tokio::sync::mpsc::unbounded_channel();
 
     let mind = crate::mind::Mind::new(config, ui_tx.clone(), turn_tx);
-    mind.init().await;
 
-    let ui_agent = mind.agent.clone();
-    let shared_mind = mind.shared.clone();
     let shared_context = mind.agent.lock().await.shared_context.clone();
     let shared_active_tools = mind.agent.lock().await.active_tools.clone();
     let turn_watch = mind.turn_watch();
 
-    tokio::spawn(async move {
-        mind.run(mind_rx, turn_rx).await;
-    });
+    let mut result = Ok(());
+    tokio_scoped::scope(|s| {
+        // Mind event loop — init + run
+        s.spawn(async {
+            mind.init().await;
+            mind.run(mind_rx, turn_rx).await;
+        });
 
-    run(
-        tui::App::new(String::new(), shared_context, shared_active_tools),
-        ui_agent, shared_mind, turn_watch, mind_tx, ui_tx, ui_rx,
-    ).await
+        // UI event loop
+        s.spawn(async {
+            result = run(
+                tui::App::new(String::new(), shared_context, shared_active_tools),
+                &mind.agent, &mind.shared, turn_watch, mind_tx, ui_tx, ui_rx,
+            ).await;
+        });
+    });
+    result
 }
 
 fn send_help(ui_tx: &ui_channel::UiSender) {
@@ -210,8 +216,8 @@ pub async fn cmd_switch_model(
 
 pub async fn run(
     mut app: tui::App,
-    agent: Arc<Mutex<Agent>>,
-    shared_mind: crate::mind::SharedMindState,
+    agent: &Arc<Mutex<Agent>>,
+    shared_mind: &crate::mind::SharedMindState,
     turn_watch: tokio::sync::watch::Receiver<bool>,
     mind_tx: tokio::sync::mpsc::UnboundedSender<MindCommand>,
     ui_tx: ui_channel::UiSender,