- Remove use_joinir_for_array_filter() from env.rs (9 lines) Route B is now default, env flag no longer needed - Remove next_var_id() from ast_lowerer.rs (7 lines) Duplicate of alloc_var() method Cumulative deletion: 51 lines (35 + 16) Tests: 5/5 Phase 40 PASS 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>