fix(#2290): drop redundant async blocks around sync_tmpfiles spawn

hive-c0re/src/actions.rs

@@ -969,7 +969,7 @@ pub async fn destroy(coord: &Arc<Coordinator>, name: &str, purge: bool) -> Resul
     coord.emit_schedules_snapshot();
     // Update tmpfiles.d to remove the destroyed agent's dirs from the
     // boot-time pre-creation list. Best-effort: failure is logged only.
-    tokio::spawn(async { lifecycle::sync_tmpfiles().await });
+    tokio::spawn(lifecycle::sync_tmpfiles());
     Ok(())
 }
 

hive-c0re/src/main.rs

@@ -286,9 +286,7 @@ async fn cmd_serve(
     // Sync /etc/tmpfiles.d/hyperhive-agents.conf so agent runtime dirs are
     // pre-declared for the next boot. Best-effort background task — a failure
     // here must not block hive-c0re startup. See lifecycle::sync_tmpfiles.
-    tokio::spawn(async {
-        hive_c0re::lifecycle::sync_tmpfiles().await;
-    });
+    tokio::spawn(hive_c0re::lifecycle::sync_tmpfiles());
     // Auto-update in the background — don't block service start.
     // Sub-agent rebuilds can take tens of seconds; we want the admin
     // socket up immediately.

hive-c0re/src/server.rs

@@ -217,7 +217,7 @@ async fn handle_spawn(coord: &Arc<Coordinator>, name: &str) -> Result<HostRespon
                 sha: None,
             });
             // Update tmpfiles.d so the new agent's dirs survive a reboot.
-            tokio::spawn(async { lifecycle::sync_tmpfiles().await });
+            tokio::spawn(lifecycle::sync_tmpfiles());
         }
         Err(e) => {
             // Roll back socket registration if container creation failed.