feat: 增强知识库功能，优化索引和RAG检索

server/src/app/services/knowledge_normalizer.py

@@ -83,24 +83,23 @@ class KnowledgeNormalizationService:
             if rendered:
                 normalized_tables.append(f"## {candidate.title}\n\n{rendered}")
 
-        parts: list[str] = []
+        appendix_parts: list[str] = []
         if section_appendix:
-            parts.append(section_appendix)
+            appendix_parts.append(section_appendix)
         if answer_clue_appendix:
-            parts.append(answer_clue_appendix)
+            appendix_parts.append(answer_clue_appendix)
         if normalized_tables:
             appendix = "\n\n".join(normalized_tables)
-            parts.append(
+            appendix_parts.append(
                 "# 结构化表格补充\n\n"
                 "以下表格由知识归纳阶段依据原文重新整理，供问答检索时优先理解行列关系。\n\n"
                 f"{appendix}"
             )
 
-        if not parts:
+        if not appendix_parts:
             return normalized_text
 
-        parts.append(f"# 原文\n\n{normalized_text}")
-        return "\n\n".join(parts)
+        return "\n\n".join([normalized_text, *appendix_parts])
 
     @staticmethod
     def _extract_table_candidates(text: str) -> list[TableCandidate]: