hive-c0re: push Rebuilt as a todo, not a broker message

hive-c0re/src/actions.rs

@@ -777,16 +777,22 @@ async fn finish_approval(
         // lifecycle event. (It is never a first spawn — the agent already
         // exists — so it never needs the Spawned arm above.)
         ApprovalKind::MergeConfigPr => {
-            coord.notify_submitter(
-                approval.id,
-                &HelperEvent::Rebuilt {
-                    agent: approval.agent.to_string(),
-                    ok,
-                    note,
-                    sha: approval.fetched_sha.clone(),
-                    tag: terminal_tag,
-                },
+            let summary = crate::coordinator::rebuilt_todo_summary(
+                approval.agent.as_str(),
+                ok,
+                note.as_deref(),
+                approval.fetched_sha.as_deref(),
+                terminal_tag.as_deref(),
             );
+            coord
+                .push_todo_submitter(
+                    approval.id,
+                    "core",
+                    Some(format!("rebuilt:{}", approval.agent)),
+                    summary,
+                    None,
+                )
+                .await;
         }
         // UpdateMetaInputs / SchedulePrompt: ApprovalResolved already
         // carries the result. No separate lifecycle event needed.