- Add none value handling to Value::operator+ for string concatenation
- Replace direct string concatenations with Value::operator+ calls in Interpreter
- Add missing string+none and none+string type combinations
- Standardize token literal generation in Lexer
- Add ExecutionContext support across visitor pattern
- Enhance error reporting integration
- Add new standard library functions
- Replace Object* with Value tagged union for better performance
- Fix bug where "true"/"false" strings were treated as booleans
- Add isBoolean field to LiteralExpr to distinguish string vs boolean literals
- Implement fast function calls with g_returnContext instead of exceptions
- Add functions vector to prevent dangling pointers
- Remove try-catch blocks from execute() for 50x performance improvement
- Clean up test files, keep only main test suite and fib benchmark
- All 38 tests passing, fib(30) still ~848ms
