Keep active task transcripts in memory for instant task switching

web/src/lead.ts

@@ -1,11 +1,12 @@
 import { post } from "./api.js";
 import { h } from "./dom.js";
-import { currentLead, state } from "./state.js";
+import { currentLead, leadLoading, state } from "./state.js";
 import { compactButton, mountChat, type ChatSource, type Head } from "./task.js";
 
 const leadSource: ChatSource = {
   key: () => "lead",
   events: () => state.leadTranscript,
+  loading: leadLoading,
   session: currentLead,
   root: () => "",
   taskId: () => undefined,
@@ -13,6 +14,7 @@ const leadSource: ChatSource = {
   refreshTopics: ["lead.sessions"],
   transcriptTopic: "lead.transcript",
   streamTopic: "lead.stream",
+  readyTopic: "lead.ready",
   empty: "",
   canSend: () => true,
   placeholder: "Message your lead. Paste or drop images to attach them.",