- Create typed attributes struct for each mixin call with optional fields (class, id, style)
- Use unique variable names (mixin_attrs_N) to avoid shadowing in nested mixin calls
- Track current attributes variable for buildAccessor to resolve attributes.class correctly
- Only suppress unused variable warning when attributes aren't actually accessed
- HTML-escape double quotes as " in backtick template literals for valid attribute values
- Merge shorthand classes (.alert) with class attribute values instead of emitting duplicates
- Handle string concatenation expressions in class attributes (e.g., class="btn btn-" + type)
