make agent_config_pending async — the sync git fork on every sweep starved the runtime under IO load

hive-c0re/src/auto_update.rs

@@ -38,9 +38,15 @@ pub fn current_flake_rev(hyperhive_flake: &str) -> Option<String> {
 /// deployed (i.e. the applied HEAD differs from the sha currently locked in
 /// meta's flake.lock). This is the semantic the dashboard `needs_update` chip
 /// conveys: "there is a config change ready to apply via rebuild."
-#[must_use]
-pub fn agent_config_pending(name: &str, deployed_sha: Option<&str>) -> bool {
-    let applied_head = std::process::Command::new("git")
+///
+/// Async on purpose: this runs per agent inside `container_view::build_all`,
+/// which fires on the ~10s dashboard sweep, every `AgentStatus` request, and
+/// every `rescan_containers_and_emit` after a lifecycle step. A synchronous
+/// `git` fork here blocks a tokio worker for the whole exec — under
+/// nix-build disk saturation that's long enough that concurrent sweeps
+/// starved the runtime and stalled the per-agent sockets.
+pub async fn agent_config_pending(name: &str, deployed_sha: Option<&str>) -> bool {
+    let applied_head = tokio::process::Command::new("git")
         .args([
             "-C",
             &format!("/var/lib/hyperhive/applied/{name}"),
@@ -48,6 +54,7 @@ pub fn agent_config_pending(name: &str, deployed_sha: Option<&str>) -> bool {
             "HEAD",
         ])
         .output()
+        .await
         .ok()
         .filter(|o| o.status.success())
         .and_then(|o| String::from_utf8(o.stdout).ok())

hive-c0re/src/container_view.rs

@@ -70,7 +70,7 @@ pub async fn build_all(coord: &Coordinator) -> Vec<ContainerView> {
         let deployed_full = locked
             .get(&format!("agent-{logical}"))
             .map(std::string::String::as_str);
-        let needs_update = crate::auto_update::agent_config_pending(&logical, deployed_full);
+        let needs_update = crate::auto_update::agent_config_pending(&logical, deployed_full).await;
         let deployed_sha = deployed_full.map(|s| s[..s.len().min(12)].to_owned());
         let pending_reminders = coord
             .broker