fix(routing): correct document-preview route path and update API port

Update the document-preview route path to be relative under the chunk route
and add port number to the API base URL in environment configuration

src/routes/index.tsx

@@ -40,7 +40,7 @@ const AppRoutes = () => {
       <Route path="chunk">
         <Route path="parsed-result" element={<ChunkParsedResult />} />
         {/* 文档预览页面路由 */}
-        <Route path="/document-preview/:kb_id/:doc_id" element={<DocumentPreview />} />
+        <Route path="document-preview/:kb_id/:doc_id" element={<DocumentPreview />} />
       </Route>
 
       {/* 处理未匹配的路由 */}