feat: initialize sunrise with 100-player shared rooms

tests/gisamun.test.ts

@@ -0,0 +1,40 @@
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { readFileSync } from 'node:fs';
+import { Mesh, MeshBasicMaterial, Raycaster, Vector3 } from 'three';
+import { GISAMUN } from '../src/constants/gisamun.ts';
+import { isCoastalLand } from '../src/scene/coast.ts';
+import { createTerrainGeometry, validateTerrain } from '../src/scene/terrainGeometry.ts';
+import { calculateSun } from '../src/astronomy/sunCalculator.ts';
+import { directionFromAngles } from '../src/astronomy/direction.ts';
+
+const base = new URL('../public/terrain/gisamun/', import.meta.url);
+test('Gisamun observer is on land and the eastern view is sea, with both DSM tiles used', () => {
+  const meta=JSON.parse(readFileSync(new URL('metadata.json',base),'utf8'));
+  const coast=JSON.parse(readFileSync(new URL('coast.json',base),'utf8'));
+  const bytes=readFileSync(new URL('heights.f32',base));
+  const heights=new Float32Array(bytes.buffer.slice(bytes.byteOffset,bytes.byteOffset+bytes.byteLength));
+  validateTerrain(meta,heights,GISAMUN);
+  assert.ok(isCoastalLand(coast,0,0));
+  assert.equal(isCoastalLand(coast,200,0),false);
+  assert.equal(meta.sources.filter((s:{file:string})=>s.file.endsWith('.tif')).length,2);
+  assert.ok(heights.every(Number.isFinite));
+  assert.ok(heights.some(h=>h<0), 'retain below-zero Copernicus samples instead of clamping to OSM land/sea heights');
+  assert.equal(meta.corrections.osmHeightCorrection,false);
+});
+
+test('Gisamun terrain clears the October dawn sun that is blocked at Hajodae', () => {
+  const meta=JSON.parse(readFileSync(new URL('metadata.json',base),'utf8'));
+  const bytes=readFileSync(new URL('heights.f32',base));
+  const heights=new Float32Array(bytes.buffer.slice(bytes.byteOffset,bytes.byteOffset+bytes.byteLength));
+  const geometry=createTerrainGeometry(meta,heights,true), material=new MeshBasicMaterial();
+  const mesh=new Mesh(geometry,material);
+  const observer={...GISAMUN,elevation:meta.observerSurfaceElevation,eyeHeight:1.7};
+  for (const time of ['06:52','06:55','07:00']) {
+    const sun=calculateSun(new Date(`2026-10-29T${time}:00+09:00`),observer);
+    assert.ok(sun.altitude>0);
+    const ray=new Raycaster(new Vector3(0,1.7,0),new Vector3(...directionFromAngles(sun.azimuth,sun.altitude)));
+    assert.equal(ray.intersectObject(mesh).length,0,`${time} should clear the modelled terrain`);
+  }
+  geometry.dispose(); material.dispose();
+});