Fix critical encoding mismatch where calculate_on_base_code() returned
bit-field encoding (3=R1+R2, 4=R3) but runner_advancement.py charts
expected sequential encoding (3=R3, 4=R1+R2). Values 3 and 4 were
swapped, causing wrong groundball results for R1+R2 and R3-only scenarios.
Add comprehensive test coverage:
- 1184 invariant tests (structural correctness across all outcomes × base codes)
- 49 hit truth table tests (SINGLE_1/2, DOUBLE_2/3, TRIPLE, HOMERUN)
- 33 walk truth table tests (WALK, HBP with stat flag verification)
- 42 simple out truth table tests (STRIKEOUT, LINEOUT, POPOUT, WP, PB)
- 88 groundball truth table tests (GB_A/B/C × infield back/in/corners_in × locations)
Total: 2401 unit tests passing.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2a70df74bf