feat: 初始化考培练系统项目

- 从服务器拉取完整代码
- 按框架规范整理项目结构
- 配置 Drone CI 测试环境部署
- 包含后端(FastAPI)、前端(Vue3)、管理端

技术栈: Vue3 + TypeScript + FastAPI + MySQL

backend/scripts/alter_exams_add_rounds.sql

@@ -0,0 +1,36 @@
+-- 增量脚本：为exams表增加三轮得分字段
+-- 创建时间：2025-10-12
+-- 说明：简化三轮考试机制，一条考试记录存储三轮得分
+
+USE kaopeilian;
+
+-- 1. 为exams表增加三轮得分字段
+ALTER TABLE exams 
+  ADD COLUMN round1_score FLOAT NULL COMMENT '第一轮得分' AFTER score,
+  ADD COLUMN round2_score FLOAT NULL COMMENT '第二轮得分' AFTER round1_score,
+  ADD COLUMN round3_score FLOAT NULL COMMENT '第三轮得分' AFTER round2_score;
+
+-- 2. 为已存在的考试记录设置默认值（将score复制到round1_score）
+UPDATE exams 
+SET round1_score = score 
+WHERE score IS NOT NULL AND round1_score IS NULL;
+
+-- 3. 验证结果
+SELECT 
+    COUNT(*) as total_exams,
+    COUNT(round1_score) as has_round1,
+    COUNT(round2_score) as has_round2,
+    COUNT(round3_score) as has_round3
+FROM exams;
+
+-- 输出结果示例
+SELECT 
+    id, 
+    exam_name, 
+    score, 
+    round1_score, 
+    round2_score, 
+    round3_score 
+FROM exams 
+LIMIT 5;
+