✅ Phase 1 complete: Unified import system implemented and tested

Co-authored-by: moe-charm <217100418+moe-charm@users.noreply.github.com>

src/interpreter/methods/basic_methods.rs

@@ -11,7 +11,7 @@
 
 use super::super::*;
 use crate::box_trait::{StringBox, IntegerBox, BoolBox, VoidBox};
-use crate::boxes::math_box::FloatBox;
+use crate::boxes::FloatBox;
 
 impl NyashInterpreter {
     /// StringBoxのメソッド呼び出しを実行