fix(前端): 启动前清理 Next 缓存

关键改动：

- 前端 dev 启动前删除可能残留的 .next 缓存

- 新增安全路径校验，避免清理脚本误删 Web 应用外目录

Co-Authored-By: Codex GPT-5 <codex@openai.com>

apps/web/scripts/clean-next-dev-cache.mjs

@@ -0,0 +1,16 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const scriptDir = path.dirname(fileURLToPath(import.meta.url));
+const webRoot = path.resolve(scriptDir, '..');
+const nextDir = path.resolve(webRoot, '.next');
+
+if (!nextDir.startsWith(`${webRoot}${path.sep}`)) {
+  throw new Error(`Refusing to remove path outside web app: ${nextDir}`);
+}
+
+if (fs.existsSync(nextDir)) {
+  fs.rmSync(nextDir, { recursive: true, force: true });
+  console.log('[web dev] removed stale .next cache');
+}