feat: Unified registry and major code cleanup by ChatGPT5

- Unified Box Registry: Replaced 600+ line match statement with clean factory pattern
- Code cleanup: Removed unused imports, variables, and dead code
- Import fixes: Fixed RangeBox, NullBox, MapBox imports
- Transport Debug: Added Debug trait implementation for Transport interface
- WASM build: Successfully tested with wasm_playground preset ready for integration
- Performance: Build time stable, WASM package generated successfully (1.89MB)

This commit represents a major architectural improvement with the unified registry
system now fully operational, reducing code duplication and improving maintainability.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/interpreter/mod.rs

@@ -7,7 +7,7 @@
 
 // Import all necessary dependencies
 use crate::ast::{ASTNode, CatchClause};
-use crate::box_trait::{NyashBox, StringBox, IntegerBox, BoolBox, VoidBox, ArrayBox, ResultBox, ErrorBox, BoxCore};
+use crate::box_trait::{NyashBox, StringBox, IntegerBox, BoolBox, VoidBox, ErrorBox, BoxCore};
 use crate::boxes::FutureBox;
 use crate::instance_v2::InstanceBox;
 use crate::channel_box::ChannelBox;