refactor: consolidate throwIfAborted + fix isCompactionFailureError (#12463)

* refactor: consolidate throwIfAborted in outbound module

- Create abort.ts with shared throwIfAborted helper

- Update deliver.ts, message-action-runner.ts, outbound-send-service.ts

* fix: handle context overflow in isCompactionFailureError without requiring colon

src/infra/outbound/outbound-send-service.ts

@@ -6,6 +6,7 @@ import type { OutboundSendDeps } from "./deliver.js";
 import type { MessagePollResult, MessageSendResult } from "./message.js";
 import { dispatchChannelMessageAction } from "../../channels/plugins/message-actions.js";
 import { appendAssistantMessageToSessionTranscript } from "../../config/sessions.js";
+import { throwIfAborted } from "./abort.js";
 import { sendMessage, sendPoll } from "./message.js";
 
 export type OutboundGatewayContext = {
@@ -59,14 +60,6 @@ function extractToolPayload(result: AgentToolResult<unknown>): unknown {
   return result.content ?? result;
 }
 
-function throwIfAborted(abortSignal?: AbortSignal): void {
-  if (abortSignal?.aborted) {
-    const err = new Error("Message send aborted");
-    err.name = "AbortError";
-    throw err;
-  }
-}
-
 export async function executeSendAction(params: {
   ctx: OutboundSendContext;
   to: string;