fix: let channels control reply length

ChannelService previously truncated every reply at 4,000 characters and discarded the remainder before the platform adapter could handle it. Complete executor output now reaches each channel driver, while error redaction and channel-specific platform limits remain intact.

Release note: 消息通道回复不再由公共服务统一截断；完整结果现在交由微信、企业微信或钉钉按各自平台能力处理。

src/main/channels/channel-service.ts

@@ -15,14 +15,11 @@ import {
   type Outbox
 } from './channel-driver'
 
-const TRUNCATION_MARKER = '\n…（结果已截断）'
-
 export type ChannelServiceOptions = {
   allowedSenderIds?: readonly string[]
   allowGroupMessages?: boolean
   maximumConcurrency?: number
   maximumInputLength?: number
-  maximumResultLength?: number
   dedupStore?: DedupStore
   outbox?: Outbox
   onDeliveryFailure?: (error: unknown) => void
@@ -48,19 +45,6 @@ function boundedInteger(
   return candidate
 }
 
-function truncate(value: string, maximumLength: number): string {
-  if (value.length <= maximumLength) {
-    return value
-  }
-  if (maximumLength <= TRUNCATION_MARKER.length) {
-    return value.slice(0, maximumLength)
-  }
-  return (
-    value.slice(0, maximumLength - TRUNCATION_MARKER.length) +
-    TRUNCATION_MARKER
-  )
-}
-
 export function redactChannelError(value: string): string {
   return value
     .replace(/\bBearer\s+[^\s,;]+/giu, 'Bearer [已隐藏]')
@@ -84,7 +68,6 @@ export class ChannelService {
   private readonly allowGroupMessages: boolean
   private readonly maximumConcurrency: number
   private readonly maximumInputLength: number
-  private readonly maximumResultLength: number
   private readonly dedupStore: DedupStore
   private readonly outbox: Outbox
   private readonly onDeliveryFailure?: (error: unknown) => void
@@ -126,12 +109,6 @@ export class ChannelService {
       CHANNEL_LIMITS.maximumTextLength,
       '通道输入长度限制'
     )
-    this.maximumResultLength = boundedInteger(
-      options.maximumResultLength,
-      4_000,
-      CHANNEL_LIMITS.maximumResultLength,
-      '通道结果长度限制'
-    )
     this.dedupStore = options.dedupStore ?? new MemoryDedupStore()
     this.outbox = options.outbox ?? new MemoryOutbox()
     this.onDeliveryFailure = options.onDeliveryFailure
@@ -426,13 +403,13 @@ export class ChannelService {
       ...(result.output === undefined
         ? {}
         : {
-            output: truncate(result.output, this.maximumResultLength)
+            output: result.output
           }),
       ...(result.error === undefined
         ? {}
         : {
-            error: truncate(
-              redactChannelError(result.error),
+            error: redactChannelError(result.error).slice(
+              0,
               CHANNEL_LIMITS.maximumErrorLength
             )
           }),