feat(#2008): rebuild running agents first in the startup sweep

hive-c0re/src/workers/auto_update.rs

@@ -226,7 +226,9 @@ pub async fn run(coord: Arc<Coordinator>) -> Result<()> {
     // agent without an `agent_power` row is seeded from its observed
     // state (running ⇒ Up), after which the DB is authoritative.
     let mut any_stale = false;
-    let mut fanout: Vec<String> = Vec::new(); // stale ∧ wanted=Up → sweep rebuild
+    // stale ∧ wanted=Up → sweep rebuild. The bool is the agent's observed
+    // running state, used to order running agents first before submit.
+    let mut fanout: Vec<(String, bool)> = Vec::new();
     let mut drifted: Vec<String> = Vec::new(); // fresh ∧ wanted≠observed → reconcile
     let mut n_deferred = 0usize;
     let mut n_skipped = 0usize;
@@ -251,7 +253,7 @@ pub async fn run(coord: Arc<Coordinator>) -> Result<()> {
                 // Rebuild against the post-bump lock; the DAG's tail
                 // Reconcile brings the agent (back) up — covering both
                 // the running-stale and stopped-but-wanted-up cases.
-                fanout.push(name.clone());
+                fanout.push((name.clone(), running));
                 continue;
             }
             // Stale but wanted offline: no boot-time nix work — the
@@ -273,6 +275,15 @@ pub async fn run(coord: Arc<Coordinator>) -> Result<()> {
         "boot reconcile"
     );
 
+    // Rebuild running agents first. All fanout entries are wanted=Up;
+    // among them, warm the live/serving agents onto the fresh config before the
+    // stopped-but-wanted-up ones so the scarce build slots hit uptime-critical
+    // agents first. Stable sort keeps topology order (parents before children)
+    // within each running/stopped group. The `drifted` reconciles aren't sorted
+    // — they hold no build slot and run concurrently, so their order is moot.
+    fanout.sort_by_key(|(_, running)| !running);
+    let fanout: Vec<String> = fanout.into_iter().map(|(name, _)| name).collect();
+
     submit_boot_tree(&coord, any_stale, fanout, drifted, n_deferred, n_skipped);
     Ok(())
 }