feat: 为API Key添加模型限制功能

- 前端：在API Key创建和编辑表单中添加模型限制开关和标签输入
- 前端：支持动态添加/删除限制的模型列表
- 后端：更新API Key数据结构，新增enableModelRestriction和restrictedModels字段
- 后端：在中转请求时检查模型访问权限
- 修复：Enter键提交表单问题，使用@keydown.enter.prevent
- 优化：限制模型数据持久化，关闭开关时不清空数据

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/middleware/auth.js

@@ -109,7 +109,9 @@ const authenticateApiKey = async (req, res, next) => {
       name: validation.keyData.name,
       tokenLimit: validation.keyData.tokenLimit,
       claudeAccountId: validation.keyData.claudeAccountId,
-      concurrencyLimit: validation.keyData.concurrencyLimit
+      concurrencyLimit: validation.keyData.concurrencyLimit,
+      enableModelRestriction: validation.keyData.enableModelRestriction,
+      restrictedModels: validation.keyData.restrictedModels
     };
     req.usage = validation.keyData.usage;