feat(daemon): spawn_from_spec to (re)start surfaces from a persisted spec

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/spaceshd/src/surface.rs

@@ -1,10 +1,31 @@
 use spacesh_core::{snapshot::snapshot_ansi, GridSurface};
 use spacesh_core::snapshot::Snapshot;
 use spacesh_proto::{SurfaceId, WorkspaceId};
-use spacesh_pty::PtyHandle;
+use spacesh_proto::workspace::SurfaceSpec;
+use spacesh_pty::{PtyHandle, SpawnSpec};
 use tokio::sync::{broadcast, mpsc, oneshot};
 use tokio::time::{Duration, Instant};
 
+/// Spawn (or restart) a surface actor from a persisted spec. Injects
+/// SPACESH_SURFACE_ID into the child env, mirroring `new_surface`.
+pub fn spawn_from_spec(
+    id: SurfaceId,
+    workspace_id: WorkspaceId,
+    spec: &SurfaceSpec,
+    exit_tx: mpsc::UnboundedSender<(SurfaceId, i32)>,
+) -> std::io::Result<SurfaceHandle> {
+    let pty = PtyHandle::spawn(SpawnSpec {
+        command: spec.command.clone(),
+        args: spec.args.clone(),
+        cwd: std::path::PathBuf::from(&spec.cwd),
+        cols: spec.cols,
+        rows: spec.rows,
+        env: vec![("SPACESH_SURFACE_ID".into(), id.0.clone())],
+    })
+    .map_err(|e| std::io::Error::new(std::io::ErrorKind::Other, e.to_string()))?;
+    Ok(spawn_surface(id, workspace_id, pty, spec.cols, spec.rows, exit_tx))
+}
+
 const BROADCAST_CAP: usize = 1024;
 const FLUSH_INTERVAL: Duration = Duration::from_millis(6);
 const FLUSH_BYTES: usize = 16 * 1024;
@@ -181,4 +202,29 @@ mod tests {
         let (snap, _sub) = reply_rx.await.unwrap();
         assert!(snap.ansi.contains("SNAPME"), "snapshot: {:?}", snap.ansi);
     }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn spawn_from_spec_runs_the_command() {
+        let _serial = crate::test_support::serial();
+        let spec = SurfaceSpec {
+            command: "/bin/sh".into(),
+            args: vec!["-c".into(), "printf RESPAWN; sleep 0.3".into()],
+            cwd: std::env::temp_dir().to_string_lossy().into(),
+            agent_label: None, cols: 80, rows: 24, autostart: false,
+        };
+        let (exit_tx, _rx) = mpsc::unbounded_channel();
+        let handle = spawn_from_spec(SurfaceId("s_r".into()), WorkspaceId("w_1".into()), &spec, exit_tx).unwrap();
+        let (reply_tx, reply_rx) = oneshot::channel();
+        handle.tx.send(SurfaceMsg::Attach { reply: reply_tx }).await.unwrap();
+        let mut sub = reply_rx.await.unwrap();
+        let mut got = String::new();
+        let deadline = tokio::time::Instant::now() + tokio::time::Duration::from_secs(2);
+        while tokio::time::Instant::now() < deadline {
+            if let Ok(Ok(b)) = tokio::time::timeout(tokio::time::Duration::from_millis(100), sub.recv()).await {
+                got.push_str(&String::from_utf8_lossy(&b));
+                if got.contains("RESPAWN") { break; }
+            }
+        }
+        assert!(got.contains("RESPAWN"), "got: {got:?}");
+    }
 }