feat: auto-load .env via shared internal/env package

Add godotenv dependency and internal/env init loader so all cmd/
scripts get .env vars loaded automatically via blank import.

go-util/cmd/gitea-leave-orgs/main.go

@@ -8,6 +8,8 @@ import (
 	"net/http"
 	"os"
 	"strings"
+
+	_ "github.com/tiennm99/go-util/internal/env"
 )
 
 // org represents a Gitea organization.

go-util/go.mod

@@ -1,3 +1,5 @@
 module github.com/tiennm99/go-util
 
 go 1.26.1
+
+require github.com/joho/godotenv v1.5.1 // indirect

go-util/go.sum

@@ -0,0 +1,2 @@
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

go-util/internal/env/load.go

@@ -0,0 +1,16 @@
+// Package env loads .env files on init so all cmd/ scripts get env vars automatically.
+// Usage: import _ "github.com/tiennm99/go-util/internal/env"
+package env
+
+import (
+	"os"
+
+	"github.com/joho/godotenv"
+)
+
+func init() {
+	// Skip if .env doesn't exist; load if it does.
+	if _, err := os.Stat(".env"); err == nil {
+		_ = godotenv.Load()
+	}
+}