fix: add config and logger, cleanup

internal/config/config.go

@@ -0,0 +1,36 @@
+package config
+
+import (
+	"log"
+	"time"
+
+	"github.com/joho/godotenv"
+	"github.com/kelseyhightower/envconfig"
+)
+
+type Config struct {
+	// App Settings
+	LogLevel string `envconfig:"LOG_LEVEL" default:"INFO"` // INFO, DEBUG, ERROR
+	Workers  int    `envconfig:"MAX_WORKERS" default:"10"`
+
+	// Paths
+	SingBoxPath string `envconfig:"SING_BOX_PATH" default:"./bin/sing-box"`
+	
+	// Testing Parameters
+	TestURL      string        `envconfig:"TEST_URL" default:"http://cp.cloudflare.com"`
+	TcpTimeout   time.Duration `envconfig:"TCP_TIMEOUT" default:"2s"`
+	TestTimeout  time.Duration `envconfig:"TEST_TIMEOUT" default:"10s"`
+}
+
+// Load reads .env and maps variables to Config struct
+func Load() *Config {
+	// 1. Try loading .env file (optional, for local dev)
+	_ = godotenv.Load()
+
+	var cfg Config
+	// 2. Process environment variables
+	if err := envconfig.Process("", &cfg); err != nil {
+		log.Fatalf("Failed to load config: %v", err)
+	}
+	return &cfg
+}