✅ Phase 3 complete: DateTimeBox fully implemented and tested

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

src/boxes/mod.rs

@@ -77,7 +77,7 @@ pub use string_box::StringBox;
 pub use integer_box::IntegerBox;
 pub use bool_box::BoolBox;
 pub use math_box::{MathBox, FloatBox};
-pub use time_box::TimeBox;
+pub use time_box::{TimeBox, DateTimeBox};
 pub use debug_box::DebugBox;
 pub use random_box::RandomBox;
 pub use sound_box::SoundBox;