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/atlas/gen_queue.rs

@@ -31,6 +31,7 @@ use crate::atlas::attractor_matching::CityRecord;
 use crate::atlas::body_world_state::BodyWorldState;
 use crate::atlas::cascade::{run_cascade_from_heightmap, CascadeLayer};
 use crate::atlas::heightmap::{load_heightmap_png, GRID_H, GRID_W};
+use crate::atlas::region_profile::BodyParams;
 use crate::atlas::skeleton_gen::{assign_all_block_tags, generate_quarter_skeleton};
 use crate::seed::SeedChain;
 use crate::simulation::generator::{CityGenerationContext, QuarterWorldState};
@@ -76,6 +77,11 @@ pub enum GenWorkItem {
         /// time. Drives Layer-3 TerritorialStatus + spatial character (#956,
         /// D-212/214/215). `None` → `FrontierUnclaimed`.
         dominant_faction: Option<String>,
+        /// Body physical parameters for the RegionProfile layer (T-1023, D-239 §1).
+        /// Pre-resolved at dispatch time. `None` → region layer skipped for this body.
+        /// Boxed: `BodyParams` is large relative to other variants (clippy
+        /// large_enum_variant) — boxing keeps `GenWorkItem` compact.
+        body_params: Option<Box<BodyParams>>,
     },
     /// Generate a Phase 1 QuarterSkeleton for this city.
     ///
@@ -358,6 +364,7 @@ fn run_work_item(item: &GenWorkItem) -> GenCompletion {
             body_seed,
             cities,
             dominant_faction,
+            body_params,
         } => match load_heightmap_png(heightmap_path, body_id, *sea_level) {
             Ok(hm) => {
                 // Layer 1 runs at the GRID_W×GRID_H working resolution (D-202):
@@ -367,16 +374,22 @@ fn run_work_item(item: &GenWorkItem) -> GenCompletion {
                 } else {
                     hm
                 };
-                // Run through Layer 3 (settlement placement, #955): the enqueuer
-                // pre-resolved this body's settlements onto `cities` and its
-                // system faction onto `dominant_faction` (#956). A body with no
-                // settlements yields empty placements at negligible cost.
+                // Run through RegionProfile (T-1023, D-239 §1): includes Settlement
+                // and all prior layers. RegionProfile > Settlement in CascadeLayer ord
+                // so Settlement also runs when body_params is Some. When body_params
+                // is None the cascade falls back to Settlement as the terminal layer.
+                let up_to = if body_params.is_some() {
+                    CascadeLayer::RegionProfile
+                } else {
+                    CascadeLayer::Settlement
+                };
                 let snapshot = run_cascade_from_heightmap(
                     *body_seed,
                     working,
                     cities,
                     dominant_faction.as_deref(),
-                    CascadeLayer::Settlement,
+                    body_params.as_deref(),
+                    up_to,
                 );
                 GenCompletion::BodyAnalyzed {
                     body_id: body_id.clone(),
@@ -480,6 +493,7 @@ mod tests {
             body_seed: SeedChain::for_body(42, body_id),
             cities: vec![],
             dominant_faction: None,
+            body_params: None, // T-1023: no body params in queue-mechanic unit tests
         }
     }