chore: CI/CD + 前端测试 + 安全加固 + 限流完善

- 新增 .gitlab-ci.yml (lint/test/build 三阶段)
- 新增前端测试: taskStageMapper (109), api.ts (36), AuthContext (16)
- 修复旧测试: Sidebar 导航文案、MobileLayout padding 值
- python-jose → PyJWT 消除 ecdsa CVE 漏洞
- 限流中间件增加 5 个敏感端点精细限流 + 标准限流头

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/components/navigation/Sidebar.test.tsx

@@ -30,7 +30,7 @@ describe('Sidebar', () => {
     it('渲染 agency 导航项', () => {
       render(<Sidebar role="agency" />);
       expect(screen.getByText('工作台')).toBeInTheDocument();
-      expect(screen.getByText('审核决策')).toBeInTheDocument();
+      expect(screen.getByText('审核台')).toBeInTheDocument();
       expect(screen.getByText('Brief 配置')).toBeInTheDocument();
       expect(screen.getByText('达人管理')).toBeInTheDocument();
       expect(screen.getByText('数据报表')).toBeInTheDocument();
@@ -38,7 +38,7 @@ describe('Sidebar', () => {
 
     it('渲染 brand 导航项', () => {
       render(<Sidebar role="brand" />);
-      expect(screen.getByText('数据看板')).toBeInTheDocument();
+      expect(screen.getByText('项目看板')).toBeInTheDocument();
       expect(screen.getByText('AI 配置')).toBeInTheDocument();
       expect(screen.getByText('规则配置')).toBeInTheDocument();
       expect(screen.getByText('终审台')).toBeInTheDocument();