feat(feedback): 置信度评分与用户反馈机制 & 归档 confidence-feedback change

src/main/java/com/superbiz/agent/domain/entity/DiagnosisSession.java

@@ -54,6 +54,9 @@ public class DiagnosisSession {
     @Column(name = "tool_call_count")
     private Integer toolCallCount;
 
+    @Column(name = "answer", columnDefinition = "LONGTEXT")
+    private String answer;
+
     @JdbcTypeCode(SqlTypes.JSON)
     @Column(name = "self_evaluation", columnDefinition = "JSON")
     private String selfEvaluation;