add initial application structure with configuration, logging, and health check endpoints

internal/infra/db/mysql.go

@@ -0,0 +1,18 @@
+package db
+
+import (
+	"database/sql"
+
+	_ "github.com/go-sql-driver/mysql"
+
+	"epic-ent/internal/config"
+)
+
+func NewMySQL(cfg *config.Config) (*sql.DB, error) {
+	db, err := sql.Open("mysql", cfg.MySQL.DSN)
+	if err != nil {
+		return nil, err
+	}
+
+	return db, nil
+}