rebuild_queue: per-entry step label + worker phase annotations (#437)

hive-c0re/src/coordinator.rs

@@ -232,6 +232,19 @@ impl Coordinator {
         });
     }
 
+    /// Update the `step` label on a running queue entry and (if it
+    /// actually changed) re-emit the queue snapshot so the dashboard
+    /// renders the new phase. Returns `true` when the label was new
+    /// and an emit fired, mostly for tracing/logging callers; safe to
+    /// ignore. No-op when `id` is `None` (e.g. callers that aren't
+    /// running from the queue worker) or when the row isn't `Running`.
+    pub fn set_queue_step(self: &Arc<Self>, id: Option<u64>, step: &str) {
+        let Some(id) = id else { return };
+        if self.rebuild_queue.set_step(id, step) {
+            self.emit_rebuild_queue_snapshot();
+        }
+    }
+
     /// Subscribe to the shutdown watch channel. Background tasks call
     /// this at spawn time and break their loop when the receiver
     /// transitions to `true` (via `Coordinator::request_shutdown`).