Codegen: BinOp::Div now emits Math.trunc(l / r)
- Clock displays 0:1:30 instead of 0.016:1.5:30
- Affects both emit_expr and predicate_to_js
Lexer: removed duplicate 'in' keyword mapping
- InKw at line 312 is canonical, removed old In at line 338
Examples: added project-tracker.ds (each loops + cards)
