chore: move the go code into a subfolder

apps/api/internal/config/hook/enum.go

@@ -0,0 +1,24 @@
+package hook
+
+import (
+	"reflect"
+
+	"github.com/mitchellh/mapstructure"
+	"golang.org/x/exp/constraints"
+)
+
+func EnumHookFunc[T constraints.Integer](resolve func(string) (T, error)) mapstructure.DecodeHookFuncType {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{},
+	) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		if t != reflect.TypeOf(T(0)) {
+			return data, nil
+		}
+		return resolve(data.(string))
+	}
+}