feat(auth): 添加认证模块和图片批注功能（项目初始化）

- 实现用户登录、登出、密码修改等认证功能
- 添加会话管理和权限控制中间件
- 创建图片批注组件和相关API路由
- 实现批注的增删改查功能
- 添加Docker和Git忽略配置文件
- 创建系统架构文档和开发约定说明
- 集成认证模块到前端应用路由中

api/routes/annotations.ts

@@ -0,0 +1,18 @@
+import { Router, type Response } from 'express';
+import { annotationsRepository } from '../repositories/annotationsRepository.js';
+import { canWriteProject, requireWriter, type AuthRequest } from '../auth.js';
+import { database } from '../database.js';
+
+const router = Router();
+
+router.delete('/:annotationId', requireWriter, async (req: AuthRequest, res: Response) => {
+  const id = Number(req.params.annotationId);
+  if (!Number.isFinite(id)) { res.status(400).json({ error: '无效的批注 ID' }); return; }
+  const context = await database.one<{ project_id: number }>('SELECT c.project_id FROM annotations a JOIN images i ON i.id = a.image_id JOIN notes n ON n.id = i.note_id JOIN collections c ON c.id = n.collection_id WHERE a.id = ?', [id]);
+  if (!context) { res.status(404).json({ error: '批注不存在' }); return; }
+  if (!await canWriteProject(req, context.project_id)) { res.status(403).json({ error: '无权操作该批注' }); return; }
+  await annotationsRepository.remove(id);
+  res.status(204).end();
+});
+
+export default router;