feat: 实现前端卡密管理界面

- 卡密列表展示与分页功能

- 单个/批量创建卡密

- 卡密删除与批量删除

- 卡密导出功能 (file-saver)

- 启用/禁用状态切换

- 状态判断 (有效/已使用/已失效)

- Toast 通知系统 (vue-sonner)

- 登录页面错误提示优化

- 后端登录错误消息中文化

backend/cmd/main.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"log"
+	"net/http"
+	"os"
+
+	"gpt-manager-go/internal/config"
+	"gpt-manager-go/internal/db"
+	"gpt-manager-go/internal/router"
+)
+
+func main() {
+	// 加载 .env 文件
+	if err := config.LoadEnv(".env"); err != nil {
+		log.Printf("Warning: Failed to load .env file: %v", err)
+	}
+
+	// 初始化数据库连接
+	if err := db.Init(); err != nil {
+		log.Fatalf("Failed to initialize database: %v", err)
+	}
+	defer db.Close()
+
+	// 执行数据库迁移
+	if err := db.Migrate(db.DB); err != nil {
+		log.Fatalf("Failed to run migrations: %v", err)
+	}
+
+	// 设置路由
+	handler := router.SetupRoutes(db.DB)
+
+	// 获取端口
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "8080"
+	}
+
+	log.Printf("Server starting on port %s...", port)
+	if err := http.ListenAndServe(":"+port, handler); err != nil {
+		log.Fatalf("Server failed: %v", err)
+	}
+}

backend/cmd/seed/main.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+	"fmt"
+	"log"
+
+	"gpt-manager-go/internal/auth"
+	"gpt-manager-go/internal/config"
+	"gpt-manager-go/internal/db"
+	"gpt-manager-go/internal/models"
+	"gpt-manager-go/internal/repository"
+)
+
+func main() {
+	// 加载配置
+	config.LoadEnv(".env")
+
+	// 连接数据库
+	if err := db.Init(); err != nil {
+		log.Fatalf("Failed to connect database: %v", err)
+	}
+	defer db.Close()
+
+	// 执行迁移
+	if err := db.Migrate(db.DB); err != nil {
+		log.Fatalf("Failed to migrate: %v", err)
+	}
+
+	// 创建测试管理员
+	adminRepo := repository.NewAdminRepository(db.DB)
+
+	// 检查是否已存在
+	existing, _ := adminRepo.FindByUsername("admin")
+	if existing != nil {
+		fmt.Println("Admin user already exists!")
+		return
+	}
+
+	// 创建密码哈希
+	hash, err := auth.HashPassword("admin123")
+	if err != nil {
+		log.Fatalf("Failed to hash password: %v", err)
+	}
+
+	admin := &models.Admin{
+		Username:     "admin",
+		Email:        "admin@example.com",
+		PasswordHash: hash,
+		IsSuperAdmin: true,
+		IsActive:     true,
+	}
+
+	if err := adminRepo.Create(admin); err != nil {
+		log.Fatalf("Failed to create admin: %v", err)
+	}
+
+	fmt.Println("✅ Test admin created successfully!")
+	fmt.Println("   Username: admin")
+	fmt.Println("   Password: admin123")
+}