feat(pi): expire recent subagent statuses

modules/agents/pi/extensions/subagents/supervisor.ts

@@ -24,6 +24,7 @@ interface RunningChild {
 interface SupervisorOptions {
   maxConcurrent?: number;
   recentTerminalLimit?: number;
+  recentTerminalTtlMs?: number;
   timeouts?: {
     startMs?: number;
     runMs?: number;
@@ -47,6 +48,7 @@ export class Supervisor {
   private readonly children = new Map<string, RunningChild>();
   private readonly queue: RunningChild[] = [];
   private readonly waiters = new Set<() => void>();
+  private recentTerminalTimer?: ReturnType<typeof setTimeout>;
 
   constructor(
     private readonly runner: ChildRunner,
@@ -76,6 +78,7 @@ export class Supervisor {
     const active = statuses.filter((status) => !isTerminal(status.state));
     const terminal = statuses
       .filter((status) => isTerminal(status.state))
+      .filter((status) => this.isRecentTerminal(status))
       .sort((a, b) => Date.parse(b.completedAt ?? b.startedAt) - Date.parse(a.completedAt ?? a.startedAt))
       .slice(0, this.options.recentTerminalLimit ?? 10);
     return [...active, ...terminal];
@@ -134,6 +137,7 @@ export class Supervisor {
   }
 
   async shutdown(): Promise<void> {
+    this.clearRecentTerminalTimer();
     await Promise.allSettled(
       [...this.children.values()].map(async (child) => {
         if (!isTerminal(child.record.status.state)) {
@@ -142,6 +146,7 @@ export class Supervisor {
         }
       }),
     );
+    this.clearRecentTerminalTimer();
   }
 
   private createChild(request: SpawnRequest): SpawnAccepted {
@@ -340,6 +345,39 @@ export class Supervisor {
   private emitChange() {
     this.options.onChange?.(this.list());
     for (const waiter of this.waiters) waiter();
+    this.scheduleRecentTerminalExpiry();
+  }
+
+  private scheduleRecentTerminalExpiry() {
+    this.clearRecentTerminalTimer();
+    const ttl = this.options.recentTerminalTtlMs;
+    if (ttl === undefined || ttl <= 0) return;
+    const now = Date.now();
+    const nextExpiryMs = [...this.children.values()]
+      .map((child) => child.record.status)
+      .filter((status) => isTerminal(status.state))
+      .map((status) => Date.parse(status.completedAt ?? status.startedAt))
+      .filter((completed) => Number.isFinite(completed))
+      .map((completed) => completed + ttl - now)
+      .filter((remaining) => remaining > 0)
+      .sort((a, b) => a - b)[0];
+    if (nextExpiryMs === undefined) return;
+    this.recentTerminalTimer = setTimeout(() => this.emitChange(), nextExpiryMs + 1);
+  }
+
+  private clearRecentTerminalTimer() {
+    if (!this.recentTerminalTimer) return;
+    clearTimeout(this.recentTerminalTimer);
+    this.recentTerminalTimer = undefined;
+  }
+
+  private isRecentTerminal(status: SubagentStatus): boolean {
+    const ttl = this.options.recentTerminalTtlMs;
+    if (ttl === undefined) return true;
+    if (ttl <= 0) return false;
+    const completed = Date.parse(status.completedAt ?? status.startedAt);
+    if (!Number.isFinite(completed)) return true;
+    return Date.now() - completed <= ttl;
   }
 
   private waitReady(ids: string[], mode: SubagentWaitMode): boolean {