- Lexer now emits a single token for the entire expression (e.g., "btn btn-" + type)
- Runtime evaluateExpression now handles + operator for string concatenation
- Added findConcatOperator to safely find operators outside quotes/brackets
The lexer would hang when encountering operators like + in attribute values
(e.g., class="btn btn-" + type). Added scanAttrValuePart to handle
expression continuation with operators (+, -, *, /).
Also cleaned up debug prints from view_engine.zig and demo/main.zig.
