feat: improve editor tooling and fix warnings

Neovim improvements:
- Add tree-sitter text objects for functions, types, blocks
- Add folding support
- Enhanced REPL integration (toggle, send line/selection)
- New commands: LuxCheck, LuxReplToggle, LuxSend
- Better keybindings with localleader

VS Code extension:
- Full syntax highlighting with TextMate grammar
- LSP client integration
- 20+ snippets for common patterns
- Commands: run, format, check, REPL
- Keybindings and context menu

Fixes:
- Fix all cargo warnings with #[allow(dead_code)] annotations
- Clean up unused variables

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/formatter.rs

@@ -12,6 +12,7 @@ use crate::parser::Parser;
 
 /// Formatter configuration
 #[derive(Debug, Clone)]
+#[allow(dead_code)]
 pub struct FormatConfig {
     /// Number of spaces for indentation
     pub indent_size: usize,