fix(boundary): 修复多库边界问题、版本管理及删除清理

多库检索与存储修复:
- RRF 融合去重改用 (collection, chunk_id) 复合键，修复同名文件结果被吞
- DocStore 存储路径加 collection 前缀，修复跨库同名切片数据覆盖
- search_multiple 去重改用复合键
- chunk_id 解析改用 rsplit 兼容下划线文件名

上传与版本管理修复:
- 同名文件上传改为覆盖模式，自动清理旧切片
- 修复首次上传不创建版本记录
- 修复覆盖上传版本号回退到 v1
- sync ADDED 分支改用动态版本号生成
- _generate_version_id 改为基于全部版本递增
- 废止/恢复操作同步 SQLite 版本记录
- mark_document_as_superseded 改为仅更新 SQLite

删除清理修复:
- 删除文档时同步清理 SQLite 版本记录和变更日志
- 删除向量库时同步清理该库所有版本记录
- cleanup 改为清理 SQLite 记录而非 ChromaDB

测试:
- test_version_management.py: 27 条版本管理单元测试
- test_edge_cases.py: 28 条边界用例测试
- test_upload_dedup.py: 5 条上传去重测试
- e2e_risk_test.py: 27 条端到端风险测试

文档:
- 新增风险边界问题修复注意事项.md（面向后端的对接文档）
- 新增向量库边界风险分析.md
- 更新多篇现有文档

knowledge/document.py

@@ -43,7 +43,7 @@ class DocumentMixin:
         ]
 
     def delete_document(self, kb_name: str, filename: str) -> int:
-        """从向量库删除文档"""
+        """从向量库删除文档，并清理 SQLite 版本记录"""
         collection = self.get_collection(kb_name)
         if not collection:
             return 0
@@ -56,6 +56,22 @@ class DocumentMixin:
         collection.delete(ids=result['ids'])
         deleted = len(result['ids'])
 
+        # 清理 SQLite 版本记录和变更日志
+        try:
+            from data.db import get_connection
+            with get_connection("knowledge") as conn:
+                conn.execute(
+                    "DELETE FROM document_versions WHERE collection = ? AND document_id = ?",
+                    (kb_name, filename)
+                )
+                conn.execute(
+                    "DELETE FROM version_change_logs WHERE collection = ? AND document_id = ?",
+                    (kb_name, filename)
+                )
+                conn.commit()
+        except Exception as e:
+            logger.warning(f"清理版本记录失败: {e}")
+
         logger.info(f"从 {kb_name} 删除文档: {filename}, 片段数: {deleted}")
         return deleted
 
@@ -66,7 +82,7 @@ class DocumentMixin:
         reason: str = "制度废止",
         deprecated_by: str = ""
     ) -> Dict:
-        """软删除文档 - 将chunks状态标记为deprecated"""
+        """软删除文档 - 将chunks状态标记为deprecated，并同步 SQLite 版本记录"""
         collection = self.get_collection(kb_name)
         if not collection:
             return {"success": False, "error": "向量库不存在"}
@@ -97,6 +113,30 @@ class DocumentMixin:
 
         logger.info(f"软删除文档: {kb_name}/{filename}, chunks: {len(result['ids'])}, 原因: {reason}")
 
+        # 同步 SQLite 版本记录
+        try:
+            from knowledge.document_versions import get_version_query
+            from data.db import get_connection
+            vq = get_version_query()
+            active = vq.get_active_version(kb_name, filename)
+            if active:
+                with get_connection("knowledge") as conn:
+                    conn.execute("""
+                        UPDATE document_versions
+                        SET status='deprecated', deprecated_date=?, deprecated_reason=?
+                        WHERE collection=? AND document_id=? AND version=?
+                    """, (deprecated_date, reason, kb_name, filename, active.version))
+                    conn.commit()
+                vq.log_version_change(
+                    kb_name, filename,
+                    change_type="deprecate",
+                    old_version=active.version,
+                    old_status="active", new_status="deprecated",
+                    reason=reason, changed_by=deprecated_by
+                )
+        except Exception as e:
+            logger.warning(f"同步版本记录失败: {e}")
+
         return {
             "success": True,
             "deprecated_chunks": len(result['ids']),
@@ -106,7 +146,7 @@ class DocumentMixin:
         }
 
     def restore_document(self, kb_name: str, filename: str) -> Dict:
-        """恢复已废止的文档"""
+        """恢复已废止的文档，并同步 SQLite 版本记录"""
         collection = self.get_collection(kb_name)
         if not collection:
             return {"success": False, "error": "向量库不存在"}
@@ -142,6 +182,32 @@ class DocumentMixin:
 
         logger.info(f"恢复文档: {kb_name}/{filename}, chunks: {len(result['ids'])}")
 
+        # 同步 SQLite 版本记录
+        try:
+            from knowledge.document_versions import get_version_query
+            from data.db import get_connection
+            vq = get_version_query()
+            history = vq.get_document_history(kb_name, filename)
+            deprecated_ver = next(
+                (v for v in history if v.status.value == 'deprecated'), None
+            )
+            if deprecated_ver:
+                with get_connection("knowledge") as conn:
+                    conn.execute("""
+                        UPDATE document_versions
+                        SET status='active', deprecated_date=NULL, deprecated_reason=NULL
+                        WHERE collection=? AND document_id=? AND version=?
+                    """, (kb_name, filename, deprecated_ver.version))
+                    conn.commit()
+                vq.log_version_change(
+                    kb_name, filename,
+                    change_type="restore",
+                    old_version=deprecated_ver.version,
+                    old_status="deprecated", new_status="active"
+                )
+        except Exception as e:
+            logger.warning(f"同步版本记录失败: {e}")
+
         return {
             "success": True,
             "restored_chunks": len(result['ids']),