fix: 修复重新导入的模块数缺失、名称被覆盖与 URL 抓取报错

- 项目详情接口 _count 漏 select modules，重新导入弹框因此显示「undefined 个模块」
- 重新导入不再用文档中的 name/description 覆盖用户自行设置的项目名称与描述
- URL 抓取失败原因此前被完全吞掉，只剩无信息量的 502：前端改为预判混合内容、
  跳过必然超时的内网服务端代理、直连加超时，并抛出带错误码的 SpecFetchError
- 服务端代理加 15s 超时并始终返回 JSON，不再挂到 nginx 超时返回 HTML 错误页
- 新增 SpecFetchErrorNotice 组件，跨域类失败时可展开具体的 CORS 配置引导
- nginx /api/ 补 client_max_body_size 12m，避免大文档在 nginx 层被 413 挡掉

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

packages/server/src/routes/fetch-spec.ts

@@ -4,26 +4,47 @@ import { requireAuth } from '../middleware/auth.js';
 const router: RouterType = Router();
 router.use(requireAuth);
 
-// CORS proxy: frontend calls this when direct fetch is blocked by CORS
+// 服务端兜底抓取：只有当浏览器直连被 CORS / 混合内容拦截时前端才会调用这里。
+// 目标地址若是内网 / VPN 资源，服务器通常访问不到，必须快速失败并返回 JSON，
+// 否则请求会挂到 nginx 超时，前端只能看到一个没有信息量的 502/504 HTML 页面。
+const FETCH_TIMEOUT_MS = 15_000;
+
 router.get('/', async (req, res) => {
   const specUrl = req.query.url as string;
-  if (!specUrl || !specUrl.startsWith('http')) {
-    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: 'Provide a valid URL' } });
+  let target: URL;
+  try {
+    target = new URL(specUrl);
+    if (target.protocol !== 'http:' && target.protocol !== 'https:') throw new Error('bad protocol');
+  } catch {
+    res.status(400).json({ success: false, error: { code: 'VALIDATION', message: 'Provide a valid http(s) URL' } });
     return;
   }
 
   try {
-    const response = await fetch(specUrl, {
+    const response = await fetch(target.toString(), {
       headers: { Accept: 'application/json, application/yaml, text/yaml, text/plain, */*' },
+      signal: AbortSignal.timeout(FETCH_TIMEOUT_MS),
     });
     if (!response.ok) {
-      res.status(502).json({ success: false, error: { code: 'FETCH_FAILED', message: `Remote server returned ${response.status}` } });
+      res.status(502).json({
+        success: false,
+        error: { code: 'FETCH_FAILED', message: `Remote server returned ${response.status}` },
+      });
       return;
     }
     const text = await response.text();
     res.json({ success: true, data: { content: text, contentType: response.headers.get('content-type') || '' } });
   } catch (err) {
-    res.status(502).json({ success: false, error: { code: 'FETCH_FAILED', message: err instanceof Error ? err.message : 'Failed to fetch URL' } });
+    const timedOut = err instanceof Error && (err.name === 'TimeoutError' || err.name === 'AbortError');
+    res.status(502).json({
+      success: false,
+      error: {
+        code: timedOut ? 'FETCH_TIMEOUT' : 'FETCH_FAILED',
+        message: timedOut
+          ? `Timed out after ${FETCH_TIMEOUT_MS / 1000}s — the server cannot reach ${target.host}`
+          : `${err instanceof Error ? err.message : 'Failed to fetch URL'} (${target.host})`,
+      },
+    });
   }
 });
 

packages/server/src/routes/import.ts

@@ -29,10 +29,11 @@ router.post('/:id/reimport', async (req, res) => {
       await tx.endpoint.deleteMany({ where: { projectId: project.id } });
       await tx.module.deleteMany({ where: { projectId: project.id } });
 
+      // 只更新文档本体，项目名称与描述由用户自行维护，重新导入不覆盖
       await tx.project.update({
         where: { id: project.id },
         data: {
-          name: parsed.name, description: parsed.description, baseUrl: parsed.baseUrl,
+          baseUrl: parsed.baseUrl,
           openApiSpec: parsed.spec as any, openApiVersion: parsed.openApiVersion,
         },
       });

packages/server/src/routes/projects.ts

@@ -88,7 +88,7 @@ router.get('/:id', async (req, res) => {
         include: { _count: { select: { endpoints: true } } },
         orderBy: { sortOrder: 'asc' },
       },
-      _count: { select: { endpoints: true } },
+      _count: { select: { endpoints: true, modules: true } },
     },
   });
   if (!project) {