- New DigitPosPromoter Box for cascading indexOf pattern detection - Two-tier promotion strategy: A-3 Trim → A-4 DigitPos fallback - Unit tests 6/6 PASS (comparison operators, cascading dependency) - Promotion verified: digit_pos → is_digit_pos carrier ⚠️ Lowerer integration gap: lower_loop_with_break_minimal doesn't recognize promoted variables yet (Phase 224-continuation) 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>