Hoshe review findings — close silent-pass gaps in the §8 drainage tests:
- assert_drainage_monotonicity now returns whether it actually checked (chunk
had both wet and dry tiles); the three sweep tests (Alluvial/Meander/Braided
Delta) assert at least one chunk exercised the law, so a regression that
zeroes all channels fails loudly instead of passing vacuously.
- The fjord-floor test scans the full 64x64 chunk instead of a single Y=32 row
and asserts the deep-water trough exists, so the sea-level floor law can no
longer be skipped by a probe that missed the trough.
- Remove the unreferenced make_test_terrain_analysis helper (was behind
#[allow(dead_code)] with a 'future use' comment — the maintenance trap the
review flagged); make_dry_terrain_analysis covers the validation bodies.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>