fix(tui): handle timeout/error subagent statuses in /agents (#26687)

Accept delegation timeout/error statuses in the TUI subagent model, normalize unknown status strings defensively, and harden /agents overlay rendering/sorting so unknown statuses cannot crash glyph/color lookup. Add regression tests for live event normalization and disk snapshot replay.

ui-tui/src/app/createGatewayEventHandler.ts

@@ -13,7 +13,7 @@ import { rpcErrorMessage } from '../lib/rpc.js'
 import { topLevelSubagents } from '../lib/subagentTree.js'
 import { formatToolCall, stripAnsi } from '../lib/text.js'
 import { fromSkin } from '../theme.js'
-import type { Msg, SubagentProgress } from '../types.js'
+import type { Msg, SubagentProgress, SubagentStatus } from '../types.js'
 
 import { applyDelegationStatus, getDelegationState } from './delegationStore.js'
 import type { GatewayEventHandlerContext } from './interfaces.js'
@@ -54,6 +54,26 @@ const pushThinking = pushUnique(6)
 const pushNote = pushUnique(6)
 const pushTool = pushUnique(8)
 
+const KNOWN_SUBAGENT_STATUSES = new Set<SubagentStatus>([
+  'completed',
+  'error',
+  'failed',
+  'interrupted',
+  'queued',
+  'running',
+  'timeout'
+])
+
+const normalizeSubagentStatus = (status: unknown, fallback: SubagentStatus): SubagentStatus => {
+  if (typeof status !== 'string') {
+    return fallback
+  }
+
+  const normalized = status.toLowerCase() as SubagentStatus
+
+  return KNOWN_SUBAGENT_STATUSES.has(normalized) ? normalized : fallback
+}
+
 export function createGatewayEventHandler(ctx: GatewayEventHandlerContext): (ev: GatewayEvent) => void {
   const { rpc } = ctx.gateway
   const { STARTUP_RESUME_ID, newSession, resumeById, setCatalog } = ctx.session
@@ -180,8 +200,9 @@ export function createGatewayEventHandler(ctx: GatewayEventHandlerContext): (ev:
 
   // Terminal statuses are never overwritten by late-arriving live events —
   // otherwise a stale `subagent.start` / `spawn_requested` can clobber a
-  // `failed` or `interrupted` terminal state (Copilot review #14045).
-  const isTerminalStatus = (s: SubagentProgress['status']) => s === 'completed' || s === 'failed' || s === 'interrupted'
+  // terminal state from complete (failed/interrupted/timeout/error).
+  const isTerminalStatus = (s: SubagentProgress['status']) =>
+    s === 'completed' || s === 'error' || s === 'failed' || s === 'interrupted' || s === 'timeout'
 
   const keepTerminalElseRunning = (s: SubagentProgress['status']) => (isTerminalStatus(s) ? s : 'running')
 
@@ -648,7 +669,7 @@ export function createGatewayEventHandler(ctx: GatewayEventHandlerContext): (ev:
           ev.payload,
           c => ({
             durationSeconds: ev.payload.duration_seconds ?? c.durationSeconds,
-            status: ev.payload.status ?? 'completed',
+            status: normalizeSubagentStatus(ev.payload.status, 'completed'),
             summary: ev.payload.summary || ev.payload.text || c.summary
           }),
           { createIfMissing: false }

ui-tui/src/app/spawnHistoryStore.ts

@@ -1,7 +1,7 @@
 import { atom } from 'nanostores'
 
 import type { SpawnTreeLoadResponse } from '../gatewayTypes.js'
-import type { SubagentProgress } from '../types.js'
+import type { SubagentProgress, SubagentStatus } from '../types.js'
 
 export interface SpawnSnapshot {
   finishedAt: number
@@ -21,6 +21,26 @@ export interface SpawnDiffPair {
 
 const HISTORY_LIMIT = 10
 
+const KNOWN_SUBAGENT_STATUSES = new Set<SubagentStatus>([
+  'completed',
+  'error',
+  'failed',
+  'interrupted',
+  'queued',
+  'running',
+  'timeout'
+])
+
+const normalizeSubagentStatus = (status: unknown, fallback: SubagentStatus): SubagentStatus => {
+  if (typeof status !== 'string') {
+    return fallback
+  }
+
+  const normalized = status.toLowerCase() as SubagentStatus
+
+  return KNOWN_SUBAGENT_STATUSES.has(normalized) ? normalized : fallback
+}
+
 export const $spawnHistory = atom<SpawnSnapshot[]>([])
 export const $spawnDiff = atom<null | SpawnDiffPair>(null)
 
@@ -128,7 +148,7 @@ function normaliseSubagent(raw: unknown): SubagentProgress {
     parentId: s(o.parentId) ?? null,
     reasoningTokens: n(o.reasoningTokens),
     startedAt: n(o.startedAt),
-    status: (s(o.status) as SubagentProgress['status']) ?? 'completed',
+    status: normalizeSubagentStatus(o.status, 'completed'),
     summary: s(o.summary),
     taskCount: typeof o.taskCount === 'number' ? o.taskCount : 1,
     thinking: (arr<string>(o.thinking) ?? []).filter(x => typeof x === 'string'),