- Add submitSubstitution() method that routes to appropriate internal method
- Remove individual substitution methods from exports (now internal only)
- Add validation for defensive_replacement requiring position parameter
- Update tests to use unified wrapper, add test for validation error
Fixes CRIT-001: Game page called non-existent submitSubstitution method
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
