feat(rag): 添加文件相对路径支持功能

- 在FileInfo DTO中新增relativePath字段
- 实现文件相对路径的规范化处理逻辑
- 将文件相对路径存储到元数据中
- 前端添加文件路径解析和显示功能
- 优化路径分隔符统一处理机制
- 更新文件列表展示逻辑以支持路径层级结构

frontend/src/pages/KnowledgeBase/Detail/KnowledgeBaseDetail.tsx

@@ -57,14 +57,19 @@ type KBFileRow = KBFile & {
   fileCount?: number;
 };
 
-const normalizePath = (value?: string) => (value ?? "").replace(/\\/g, "/");
+const PATH_SEPARATOR = "/";
+const RELATIVE_PATH_KEY = "relativePath";
+const normalizePath = (value?: string) =>
+  (value ?? "").replace(/\\/g, PATH_SEPARATOR);
 
 const normalizePrefix = (value?: string) => {
   const trimmed = normalizePath(value).replace(/^\/+/, "").trim();
   if (!trimmed) {
     return "";
   }
-  return trimmed.endsWith("/") ? trimmed : `${trimmed}/`;
+  return trimmed.endsWith(PATH_SEPARATOR)
+    ? trimmed
+    : `${trimmed}${PATH_SEPARATOR}`;
 };
 
 const splitRelativePath = (fullPath: string, prefix: string) => {
@@ -72,7 +77,17 @@ const splitRelativePath = (fullPath: string, prefix: string) => {
     return [];
   }
   const remainder = fullPath.slice(prefix.length);
-  return remainder.split("/").filter(Boolean);
+  return remainder.split(PATH_SEPARATOR).filter(Boolean);
+};
+
+const resolveFileRelativePath = (file: KBFile) => {
+  const metadata = file?.metadata as Record<string, unknown> | undefined;
+  const metadataPath =
+    metadata && typeof metadata[RELATIVE_PATH_KEY] === "string"
+      ? String(metadata[RELATIVE_PATH_KEY])
+      : "";
+  const rawPath = metadataPath || file.fileName || file.name || "";
+  return normalizePath(rawPath).replace(/^\/+/, "");
 };
 
 const KnowledgeBaseDetailPage: React.FC = () => {
@@ -196,9 +211,11 @@ const KnowledgeBaseDetailPage: React.FC = () => {
       return;
     }
     const trimmed = currentPrefix.replace(/\/$/, "");
-    const parts = trimmed.split("/").filter(Boolean);
+    const parts = trimmed.split(PATH_SEPARATOR).filter(Boolean);
     parts.pop();
-    const parentPrefix = parts.length ? `${parts.join("/")}/` : "";
+    const parentPrefix = parts.length
+      ? `${parts.join(PATH_SEPARATOR)}${PATH_SEPARATOR}`
+      : "";
     setFilePrefix(parentPrefix);
   };
 
@@ -210,7 +227,7 @@ const KnowledgeBaseDetailPage: React.FC = () => {
     const directoryPrefix = normalizePrefix(`${currentPrefix}${directoryName}`);
     const targetIds = allFiles
       .filter((file) => {
-        const fullPath = normalizePath(file.fileName || file.name);
+        const fullPath = resolveFileRelativePath(file);
         return fullPath.startsWith(directoryPrefix);
       })
       .map((file) => file.id);
@@ -245,7 +262,7 @@ const KnowledgeBaseDetailPage: React.FC = () => {
     const fileItems: KBFileRow[] = [];
 
     allFiles.forEach((file) => {
-      const fullPath = normalizePath(file.fileName || file.name);
+      const fullPath = resolveFileRelativePath(file);
       if (!fullPath) {
         return;
       }
@@ -278,10 +295,11 @@ const KnowledgeBaseDetailPage: React.FC = () => {
         return;
       }
 
+      const displayName = file.fileName || leafName;
       fileItems.push({
         ...file,
-        name: leafName,
-        displayName: leafName,
+        name: displayName,
+        displayName,
         fullPath,
       });
     });