fix(maestro): clear worktree from the session clone on natural exit

mark_session_dead cleared blocked_work on the local session clone
written to the sidecar, but not worktree — so a pristine tree the
daemon just removed stayed named in the sidecar, and recovery from
that sidecar advertised a branch and path that no longer exist.

Refs #172.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

crates/maestro-daemon/src/session.rs

@@ -1540,6 +1540,7 @@ async fn mark_session_dead(inner: &Arc<Inner>, id: Uuid) {
             // The tree is settled (removed); a stale "in the way" would
             // describe something the session no longer holds.
             session.blocked_work = None;
+            session.worktree = None;
             let mut sessions = inner.sessions.lock().await;
             if let Some(record) = sessions.get_mut(&id) {
                 record.session.worktree = None;

crates/maestro-daemon/tests/session_manager.rs

@@ -9,6 +9,7 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use common::{init_bare_repo, init_repo, push_all_to_origin, wait_for_async, DaemonFixture};
+use maestro_daemon::sidecar::SidecarStore;
 use maestro_daemon::SessionError;
 use maestro_protocol::CreateSessionRequest;
 use maestro_protocol::{CatalogEvent, SessionStatus, WorktreeSpec};
@@ -1304,6 +1305,65 @@ async fn natural_exit_of_a_pristine_worktree_removes_it() {
     );
 }
 
+/// #172: `mark_session_dead` clears the worktree off the in-memory record
+/// when a pristine tree settles, but the local `session` clone it writes to
+/// the sidecar and broadcasts must be cleared the same way — otherwise the
+/// sidecar keeps naming a tree the daemon just removed, and a recovery from
+/// that sidecar advertises a branch and path that no longer exist.
+#[tokio::test]
+async fn natural_exit_of_a_pristine_worktree_clears_it_from_the_sidecar() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("sidecar");
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/sidecar".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+
+    // Push everything so the branch has no unpushed commits: fully pristine.
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+
+    fx.tmux.tmux.kill_session(s.id).expect("kill tmux directly");
+    fx.manager.start_liveness_watcher(Duration::from_millis(50));
+    wait_for_async(Duration::from_secs(3), || async {
+        fx.manager.status(s.id).await == Some(SessionStatus::Dead)
+    })
+    .await;
+    wait_for_async(Duration::from_secs(3), || async {
+        fx.manager.is_settled(s.id).await == Some(true)
+    })
+    .await;
+
+    assert!(
+        !wt_path.exists(),
+        "a pristine worktree leaves nothing behind"
+    );
+
+    let sidecar = SidecarStore::new(fx.sidecar_dir())
+        .read(s.id)
+        .expect("sidecar read")
+        .expect("sidecar exists");
+    assert!(
+        sidecar.worktree.is_none(),
+        "the sidecar must not keep naming a worktree the daemon already removed"
+    );
+}
+
 fn run_git_in(dir: &std::path::Path, args: &[&str]) {
     let out = Command::new("git")
         .arg("-C")