moisture_q was a single body constant (derive_moisture_q took only &BodyParams →
80 for every one of 2048 ocean-world districts), so vegetation/terrain/ecotones
were uniform — "nothing to fuzz" (the T-1080 believability bug).
- district_profile.rs: derive_moisture_q is now a body ceiling (hydrosphere+atmosphere)
× per-district gradient — latitude (equator wet → pole dry), elevation (orographic/
rain-shadow), continentality (100 − ocean_fraction_q). Integer/D-010, no new plumbing
(elev_q/ocean_fraction_q/latitude_deg already reach build_district_profile). Mirrors
D-240's temperature model. Coefficients in ClimateConstants + climate_constants.toml
[moisture_gradient] (provisional; Q-123 calibrates). Tuned so a wet body stays mostly
green with drier patches and a frozen body clamps mostly barren. + gradient unit test.
- region_profile.rs: region-tier moisture gets the region-latitude gradient (elevation/
continentality are district-scale).
- Propagates to precipitation_class / vegetation_class / morphology_zone (all read
moisture_q). D-239 §2 amended. Believability golden regenerated.
Probe (Arbour @ yolo): moisture_q distinct 1 → 49 (spread 0 → 48); 5/7 → 6/7 criteria.
Edict (frozen): moisture 0..20 ×21 — gradient within its low ceiling. Remaining fail
(vegetation-present) is the metric dividing by all-sampled incl. water on a 2/3-ocean
world — a Q-123 calibration concern, not a climate defect.
clippy --all-targets -D warnings clean; 1580 lib tests + harnesses pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>