Shows correct usage of rsi/bollinger/ema_trend condition shortcuts, entry_price and bars_since_entry ExprKind values, and func/cross_over/bin_op expressions. Also calls out common model mistakes (rsi as ExprKind, bars_since_entry as FuncName, expr_field) and adds a note that spot strategies are long-only. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>