feat(knowledge): 会话级去重 + 知识域地图注入 Planner 解决 ISS-001 重复检索

- RetrievedDocTracker: sessionId → Set<filePath> 会话级去重，LookupKnowledgeTool Step 5 过滤已检索文档
- KnowledgeDomainService: 域级聚合，LLM 生成 when_to_retrieve，构建 knowledge map YAML
- DocumentFieldEnricher: 上传时 LLM 补全 covers + whenToRetrieve（含同域文档排除上下文）
- KnowledgeDomain entity + V009 迁移: 域级元数据持久化，避免重启重复 LLM 调用
- ChatService: 注入 knowledge map 到 Planner prompt，会话结束时清理去重状态
- KnowledgeIndexService: 手写 JSON 解析替换为 Jackson ObjectMapper，启动时补建缺失域记录
- chat-planner-prompt: 新增知识库检索规则（按域 when_to_retrieve 判断，每域最多一次检索）
- doc-field-enricher-prompt / domain-summary-prompt: 外部化 LLM 提示词

src/main/java/com/superbiz/agent/service/ChatService.java

@@ -16,8 +16,10 @@ import com.superbiz.agent.hook.TokenUsageHolder;
 import com.superbiz.agent.repository.AgentStepRepository;
 import com.superbiz.agent.repository.DiagnosisSessionRepository;
 import com.superbiz.agent.tool.LookupKnowledgeTool;
+import com.superbiz.agent.tool.RetrievedDocTracker;
 import com.superbiz.agent.util.QuestionComplexity;
 import com.superbiz.agent.util.SessionContextHolder;
+import com.superbiz.agent.service.KnowledgeDomainService;
 
 import jakarta.annotation.PostConstruct;
 import org.slf4j.Logger;
@@ -79,6 +81,12 @@ public class ChatService {
     @Autowired
     private EvaluationService evaluationService;
 
+    @Autowired
+    private RetrievedDocTracker retrievedDocTracker;
+
+    @Autowired
+    private KnowledgeDomainService knowledgeDomainService;
+
     /** 多 Agent Chat 的 Prompt */
     private String chatPlannerPrompt;
     private String chatExecutorPrompt;
@@ -290,6 +298,7 @@ public class ChatService {
             diagnosisSessionRepository.save(session);
             throw e;
         } finally {
+            retrievedDocTracker.clearSession(sessionId);
             SessionContextHolder.clear();
         }
     }
@@ -383,6 +392,7 @@ public class ChatService {
             logger.error("多 Agent 执行失败", e);
             return new ChatResult("执行失败: " + e.getMessage(), sessionId);
         } finally {
+            retrievedDocTracker.clearSession(sessionId);
             SessionContextHolder.clear();
         }
     }
@@ -390,6 +400,13 @@ public class ChatService {
     private ReactAgent buildChatPlannerAgent(ChatModel chatModel, ToolCallback[] toolCallbacks,
                                              List<Map<String, String>> history) {
         StringBuilder prompt = new StringBuilder(chatPlannerPrompt);
+
+        // 注入 knowledge map
+        String knowledgeMap = knowledgeDomainService.buildKnowledgeMap();
+        if (!knowledgeMap.isBlank()) {
+            prompt.append("\n\n## 可用知识库\n\n").append(knowledgeMap);
+        }
+
         if (!history.isEmpty()) {
             prompt.append("\n\n--- 对话历史 ---\n");
             for (Map<String, String> msg : history) {
@@ -402,7 +419,6 @@ public class ChatService {
                 .description("负责拆解问题、规划步骤")
                 .model(chatModel)
                 .systemPrompt(prompt.toString())
-                // Planner 不注入工具，只能规划不能执行
                 .hooks(new AgentLoggingHook(agentStepRepository, "planner"))
                 .outputKey("planner_plan")
                 .build();