fix(#2003): start root container if present-but-stopped on hive-c0re boot

hive-c0re/src/auto_update.rs

@@ -195,6 +195,20 @@ pub async fn ensure_root_agent(coord: &Arc<Coordinator>) -> Result<()> {
         } else {
             tracing::debug!("manager container already present");
         }
+        // The root/manager is required infrastructure — it must be running
+        // after every hive-c0re (re)start. A previous bring-up can leave it
+        // *created but stopped* (e.g. a first-start failure on a fresh
+        // install, #2003): the startup sweep's rebuild only restarts a
+        // container that was already running, so without this it stays down
+        // until a manual `nixos-container start`. Unlike sub-agents there is
+        // no "deliberately stopped root" intent to honour, so start it
+        // unconditionally when it isn't running.
+        if !lifecycle::is_running(MANAGER_NAME).await {
+            tracing::info!("manager container present but not running — starting");
+            if let Err(e) = lifecycle::start(MANAGER_NAME).await {
+                tracing::warn!(error = ?e, "manager start failed");
+            }
+        }
         return Ok(());
     }
     tracing::info!("manager container missing — spawning");