- PageController: cover the legacy `/qsos` → `/contacts` redirect pair
(both the index and the id-preserving per-resource redirect), which
had no coverage since the route rename.
- Scorer property tests:
- f_to_c / c_to_f are inverses up to float epsilon, both propagate
nil, and the C→F slope is exactly 5/9.
- wind_speed_kts is non-negative, propagates nil on either axis,
and matches sqrt(u²+v²)·1.94384 (the 5-digit kts factor the
scorer uses).
- precip_to_rate_mmhr is non-negative, 0 for nil/zero/negative.
- dbz_to_rain_rate_mmhr is 0 below 5 dBZ (and for nil), and
monotonically non-decreasing above — guards against accidental
inversion of the Marshall-Palmer lookup.
Suite: 2,382 tests + 155 properties (was 2,380 + 148); coverage
71.08% → 71.12%; credo strict clean.