Make task state store-owned and signal its changes to the lead

web/src/api.gen.ts

@@ -982,8 +982,11 @@ export interface components {
             workflow_run?: string;
             /** @description With workflow: the name of the stage this task runs. */
             workflow_stage?: string;
-            /** @description Whether a review of one of the task's snapshots is running. */
-            reviewing: boolean;
+            /**
+             * @description What the task is doing, kept by the store in the same transaction as every change to it (a task.state event carries each change): merged or discarded once closed, else discarding, merging, the state of its agent's latest live session when that isn't idle, reviewing while a review runs, review_pending between a turn's end and its snapshot's review starting or being skipped, idle, or no_agent.
+             * @enum {string}
+             */
+            state: "running" | "idle" | "review_pending" | "reviewing" | "merging" | "discarding" | "merged" | "discarded" | "no_agent";
             /** @description Whether a Merge was started and its turn hasn't ended yet. */
             merging: boolean;
             /** @description Whether a Discard was started and the task isn't closed yet: its summary turn is waiting for the running turn, running, or done and the task is being removed. */

web/src/state.ts

@@ -88,6 +88,13 @@ export function currentSession(taskId: string): AgentSession | undefined {
   return state.sessions.get(taskId)?.findLast((s) => s.state !== "completed") ?? state.sessions.get(taskId)?.at(-1);
 }
 
+const workingTitles: Partial<Record<Task["state"], string>> = {
+  running: "The agent is mid-turn",
+  review_pending: "A review of the turn's work is about to start",
+  reviewing: "A review is running",
+  discarding: "Discarding",
+};
+
 export type TaskState = { kind: "answer" | "merging" | "held" | "error" | "working" | "idle"; label: string; title: string };
 
 export function taskState(task: Task): TaskState {
@@ -107,8 +114,9 @@ export function taskState(task: Task): TaskState {
   if (open.length > 0) {
     return { kind: "error", label: "Error", title: "The agent's session failed or hit a rate limit; see the inbox" };
   }
-  if (task.discarding || task.reviewing || currentSession(task.id)?.state === "running") {
-    return { kind: "working", label: "Working", title: task.discarding ? "Discarding" : task.reviewing ? "A review is running" : "The agent is mid-turn" };
+  const working = workingTitles[task.state];
+  if (working !== undefined) {
+    return { kind: "working", label: "Working", title: working };
   }
   return { kind: "idle", label: "Idle", title: "Waiting for a message" };
 }
@@ -434,6 +442,7 @@ export function handleEvent(ev: ByreEvent): void {
     case "task.discard_started":
     case "task.merged":
     case "task.discarded":
+    case "task.state":
       if (ev.project_id) {
         void loadTasks(ev.project_id);
       }
@@ -468,9 +477,6 @@ export function handleEvent(ev: ByreEvent): void {
       break;
     case "review.started":
     case "review.finished":
-      if (ev.project_id) {
-        void loadTasks(ev.project_id);
-      }
       if (state.inbox.some((i) => i.task_id === ev.task_id && i.kind === "question")) {
         void loadInbox();
       }