fix(delegate-task): retry sync tasks after runtime session errors

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/tools/delegate-task/sync-session-poller.ts

@@ -3,6 +3,7 @@ import type { SessionMessage } from "./executor-types"
 import { getDefaultSyncPollTimeoutMs, getTimingConfig } from "./timing"
 import { log } from "../../shared/logger"
 import { normalizeSDKResponse } from "../../shared"
+import { extractErrorMessage } from "../../features/background-agent/error-classifier"
 
 const NON_TERMINAL_FINISH_REASONS = new Set(["tool-calls", "unknown"])
 const PENDING_TOOL_PART_TYPES = new Set(["tool", "tool_use", "tool-call"])
@@ -32,6 +33,16 @@ async function fetchSessionMessages(
   return Array.isArray(rawData) ? (rawData as SessionMessage[]) : []
 }
 
+function getTerminalSessionError(messages: SessionMessage[]): string | null {
+  const lastAssistant = [...messages].reverse().find((msg) => msg.info?.role === "assistant")
+  if (!lastAssistant?.info || !("error" in lastAssistant.info)) {
+    return null
+  }
+
+  const errorMessage = extractErrorMessage((lastAssistant.info as { error?: unknown }).error)
+  return errorMessage && errorMessage.length > 0 ? errorMessage : "Session error"
+}
+
 export function isSessionComplete(messages: SessionMessage[]): boolean {
   let lastUser: SessionMessage | undefined
   let lastAssistant: SessionMessage | undefined
@@ -137,6 +148,12 @@ export async function pollSyncSession(
       continue
     }
 
+    const sessionError = getTerminalSessionError(messages)
+    if (sessionError) {
+      log("[task] Poll detected terminal session error", { sessionID: input.sessionID, sessionError })
+      return sessionError
+    }
+
     if (isSessionComplete(messages)) {
       log("[task] Poll complete - terminal finish detected", { sessionID: input.sessionID, pollCount })
       break