init: 初始化 AssetX 项目仓库

包含 webapp（Next.js 用户端）、webapp-back（Go 后端）、
antdesign（管理后台）、landingpage（营销落地页）、
数据库 SQL 和配置文件。

webapp-back/common/database_mysql.go

@@ -0,0 +1,64 @@
+package common
+
+import (
+	"fmt"
+	"log"
+	"time"
+
+	"github.com/gothinkster/golang-gin-realworld-example-app/config"
+	"gorm.io/driver/mysql"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+)
+
+// InitMySQL initializes MySQL database connection
+func InitMySQL() *gorm.DB {
+	cfg := config.AppConfig
+	if cfg == nil {
+		log.Fatal("Config not loaded. Please call config.Load() first")
+	}
+
+	// Build DSN
+	dsn := fmt.Sprintf("%s:%s@tcp(%s:%s)/%s?charset=utf8mb4&parseTime=True&loc=Local",
+		cfg.DBUser,
+		cfg.DBPassword,
+		cfg.DBHost,
+		cfg.DBPort,
+		cfg.DBName,
+	)
+
+	// Open database connection
+	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
+		Logger: logger.Default.LogMode(logger.Info),
+	})
+	if err != nil {
+		log.Fatal("Failed to connect to MySQL:", err)
+	}
+
+	// Get underlying sql.DB
+	sqlDB, err := db.DB()
+	if err != nil {
+		log.Fatal("Failed to get sql.DB:", err)
+	}
+
+	// Set connection pool parameters
+	sqlDB.SetMaxIdleConns(10)
+	sqlDB.SetMaxOpenConns(100)
+	sqlDB.SetConnMaxLifetime(time.Hour)
+
+	// Test connection
+	if err := sqlDB.Ping(); err != nil {
+		log.Fatal("Failed to ping MySQL:", err)
+	}
+
+	log.Println("✓ MySQL connected successfully")
+	DB = db
+	return DB
+}
+
+// InitRedis initializes Redis client (you'll need to add redis package)
+func InitRedis() {
+	// TODO: Add Redis initialization
+	// You'll need to add github.com/redis/go-redis/v9
+	log.Println("✓ Redis initialization skipped (add go-redis package)")
+}