feat(simulation): D-239 three-carrier foundation (T-1023/1024/1026)

First foundation slice of the Atlas-to-tile derivation model (epic T-974),
building the carrier layer ahead of its T-1027+ consumers.

T-1026 — Anti-squaring domain warp (D-239 §4): stateless pure
fn(seed,body_id,pos)->(f64,f64), ±8m, f64 to the final voxel then as-i32
truncation for IEEE-754 cross-target determinism. New domain_warp.rs,
SeedDomain::DomainWarp; golden-vector + cross-thread tests. Position math
only — D-010 integer discipline preserved downstream. Marked dead_code
until the T-1028 VoxelColumn pipeline consumes it.

T-1023 — RegionProfile carrier (D-239 §1,§10): new RegionProfile +
TectonicClass/GlaciationGrade/PrecipitationClass enums + BodyParams; derived
per-region river_threshold replacing the global 200 for tile consumers.
regions: BTreeMap on BodyWorldState, populated via the cascade's new
RegionProfile layer (runs when body_params is Some, else falls back to
Settlement). D-010 integer discipline, BTree ordering.

T-1024 — District climate primitives (D-239 §2): nullable temperature_c +
moisture on RegionProfile, mean-annual scalar (no clock dep; dynamic branch
deferred to Q-105). Hybrid inputs — new bodies.axial_tilt_deg column imported
from planet-gen body-defs (populate_axial_tilt_deg, 2611 bodies), luminosity
and orbital distance derived at runtime; greenhouse + diurnal-swing tables in
source-canonical climate_constants.toml. D-239 implementation note added.

cargo test: 1498 passed, 0 failed. clippy clean (pre-existing
large_enum_variant only). make check-systems-db: stamp fresh.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/src/seed.rs

@@ -94,6 +94,9 @@ pub enum SeedDomain {
     Block = 5,
     /// NPC generation (keyed by NPC StableId).
     Npc = 6,
+    /// Anti-squaring domain warp (D-239 §4, T-1026).
+    /// Keyed by per-tile position id (see `atlas::domain_warp::pos_to_id`).
+    DomainWarp = 7,
 }
 
 /// A position in the deterministic seed tree (D-224).
@@ -249,6 +252,7 @@ mod tests {
         assert_eq!(SeedDomain::Layer4Quarter as u64, 4);
         assert_eq!(SeedDomain::Block as u64, 5);
         assert_eq!(SeedDomain::Npc as u64, 6);
+        assert_eq!(SeedDomain::DomainWarp as u64, 7);
     }
 
     #[test]