refactor(agents): remove per-intent hard truncation, keep 2000-char safety net

Hard-coded INTENT_MAX_ANSWER_LENGTH limits caused mid-sentence truncation and
content loss. Length control now relies on prompt + schema description + LLM-Judge
(3 layers). Only a 2000-char safety net remains for extreme edge cases.

Also simplified followUp: non-question followUp is now always appended (prevents
model content split from silently dropping text).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/services/conversation-service/src/infrastructure/agents/coordinator/agent-loop.ts

@@ -32,7 +32,6 @@ import {
   getToolsForClaudeAPI,
 } from '../tools/coordinator-tools';
 import {
-  INTENT_MAX_ANSWER_LENGTH,
   MAX_FOLLOWUP_LENGTH,
   smartTruncate,
 } from '../schemas/coordinator-response.schema';
@@ -351,48 +350,39 @@ export async function* agentLoop(
       .map(b => b.text)
       .join('');
 
-    // ---- Structured Output 解析：从 JSON 中提取 answer，强制截断，yield ----
+    // ---- Structured Output 解析：从 JSON 中提取 answer + followUp ----
+    // 长度控制由 提示词 + Schema描述 + LLM-Judge 三层负责
+    // 这里只做 JSON 解析 + 安全网（2000字极端情况保护）
     if (params.outputConfig && responseText) {
       try {
         const parsed = JSON.parse(responseText);
         if (parsed.answer) {
-          // 按 intent 强制截断 answer
-          const maxLen = INTENT_MAX_ANSWER_LENGTH[parsed.intent] || 300;
-          const originalLen = parsed.answer.length;
-          const answer = smartTruncate(parsed.answer, maxLen);
-
-          if (originalLen > maxLen) {
-            logger.debug(
-              `[Turn ${currentTurn + 1}] Answer truncated: ${originalLen} → ${answer.length} chars (intent=${parsed.intent}, limit=${maxLen})`,
+          const SAFETY_NET = 2000; // 极端情况安全网，正常不会触发
+          let answer = parsed.answer;
+          if (answer.length > SAFETY_NET) {
+            answer = smartTruncate(answer, SAFETY_NET);
+            logger.warn(
+              `[Turn ${currentTurn + 1}] Answer hit safety net: ${parsed.answer.length} → ${answer.length} chars (intent=${parsed.intent})`,
             );
           }
 
           yield { type: 'text', content: answer, timestamp: Date.now() };
 
-          // followUp 处理：
-          // 1. 含 ？/? → 作为跟进问题输出
-          // 2. answer 未以句末标点结束 → followUp 可能是 answer 的延续部分，追加输出
-          // 3. 其余情况 → 过滤掉（内部策略备注等）
+          // followUp：含？→ 跟进问题；否则直接追加（模型可能将内容分到 followUp）
           if (parsed.followUp) {
-            const isQuestion = /？|\?/.test(parsed.followUp);
-            const answerEndsClean = /[。！？；!?]$/.test(answer.replace(/\.{3}$/, ''));
-
-            if (isQuestion) {
+            if (/？|\?/.test(parsed.followUp)) {
               const followUp = smartTruncate(parsed.followUp, MAX_FOLLOWUP_LENGTH);
               yield { type: 'text', content: '\n\n' + followUp, timestamp: Date.now() };
-            } else if (!answerEndsClean) {
-              // answer 被截断或模型将内容分到 followUp → 追加（不换行）
-              logger.debug(`[Turn ${currentTurn + 1}] followUp appended as answer continuation`);
+            } else {
+              // 非问题的 followUp 直接追加（防止内容丢失）
               yield { type: 'text', content: parsed.followUp, timestamp: Date.now() };
             }
           }
         } else {
-          // JSON 合法但缺少 answer 字段 → yield 原始文本
           yield { type: 'text', content: responseText, timestamp: Date.now() };
         }
         logger.debug(`[Turn ${currentTurn + 1}] Structured output intent: ${parsed.intent}`);
       } catch {
-        // JSON 解析失败 → 回退到原始文本
         logger.warn(`[Turn ${currentTurn + 1}] Structured output parse failed, falling back to raw text`);
         yield { type: 'text', content: responseText, timestamp: Date.now() };
       }

packages/services/conversation-service/src/infrastructure/agents/schemas/coordinator-response.schema.ts

@@ -23,21 +23,6 @@ export const CoordinatorResponseSchema = z.object({
 
 export type CoordinatorResponse = z.infer<typeof CoordinatorResponseSchema>;
 
-// ============================================================
-// Intent-based Answer Length Limits (中文字符数)
-// ============================================================
-
-/** 每种意图对应的最大 answer 长度（字符数）— 程序级硬约束 */
-export const INTENT_MAX_ANSWER_LENGTH: Record<string, number> = {
-  factual_question: 250,       // 1-3句，直接给答案
-  yes_no_question: 150,        // 1-2句，结论+理由
-  comparison_question: 300,    // 2-3句，推荐+理由
-  assessment_request: 500,     // 按需但有上限
-  objection_expression: 350,   // 共情+事实+引导（3个组件各需空间）
-  detailed_consultation: 600,  // 复杂咨询允许较长
-  casual_chat: 100,            // 1句
-};
-
 /** followUp 问题最大长度 */
 export const MAX_FOLLOWUP_LENGTH = 80;