重构项目结构：统一目录层级

- 移除 backend/.git 工作树配置
- 将原根目录文件归入 backend/ 目录
- 新增 app/、frontend/ 等模块
- 保留文件历史（自动识别重命名）

backend/services/user-service/migrations/001_init.sql

@@ -0,0 +1,51 @@
+-- 用户主表
+CREATE TABLE IF NOT EXISTS user_main (
+    id UUID PRIMARY KEY,
+    deleted BOOLEAN NOT NULL DEFAULT FALSE,
+    create_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    modify_date TIMESTAMP WITH TIME ZONE NOT NULL
+);
+
+-- 用户登录账号表
+CREATE TABLE IF NOT EXISTS user_login_account (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL,
+    account VARCHAR(100) NOT NULL,
+    deleted BOOLEAN NOT NULL DEFAULT FALSE,
+    create_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    modify_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    CONSTRAINT fk_user_login_account_user_main FOREIGN KEY (user_id) REFERENCES user_main(id)
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_user_login_account_active 
+    ON user_login_account(account) 
+    WHERE deleted = FALSE;
+
+-- 用户密码表
+CREATE TABLE IF NOT EXISTS user_login_password (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL,
+    password VARCHAR(255) NOT NULL,
+    deleted BOOLEAN NOT NULL DEFAULT FALSE,
+    create_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    modify_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    CONSTRAINT fk_user_login_password_user_main FOREIGN KEY (user_id) REFERENCES user_main(id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_user_login_password_user_id 
+    ON user_login_password(user_id);
+
+-- 用户登录邮箱表
+CREATE TABLE IF NOT EXISTS user_login_email (
+    id UUID PRIMARY KEY,
+    user_id UUID NOT NULL,
+    email VARCHAR(255) NOT NULL,
+    deleted BOOLEAN NOT NULL DEFAULT FALSE,
+    create_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    modify_date TIMESTAMP WITH TIME ZONE NOT NULL,
+    CONSTRAINT fk_user_login_email_user_main FOREIGN KEY (user_id) REFERENCES user_main(id)
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS idx_user_login_email_active 
+    ON user_login_email(email) 
+    WHERE deleted = FALSE;