Gateway: show subagent requests on the parent's card, and settle threads

gateway/src/notify.ts

@@ -91,10 +91,13 @@ export class Notifier {
     ]);
     const project = host.projects.get(thread.projectId)?.title;
     const requestId = thread.pendingRuntimeRequest?.id;
+    // A subagent's push is about the thread that delegated to it, which is the one the user knows.
+    const parent = thread.delegatedFrom?.title;
+    const text = body(phase, thread.lastError ?? null, summary);
     await this.send({
-      title: thread.title,
+      title: parent ?? thread.title,
       subtitle: project ? `${host.label} · ${project}` : host.label,
-      body: body(phase, thread.lastError ?? null, summary),
+      body: parent ? `Subagent ${thread.title}: ${text}` : text,
       category: category(phase),
       data: { hostId: host.id, threadId: thread.id, ...(requestId ? { requestId } : {}) },
       collapseId: `${host.id}:${thread.id}`.slice(0, 64),