feat(world): Poly-Haven-Materialien, Wasser, Himmel und mitlaufende Schatten

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

tools/assets/textures.mjs

@@ -0,0 +1,18 @@
+// Lädt die benötigten Poly-Haven-Texturen in 1k nach public/textures/.
+import { mkdir, writeFile } from "node:fs/promises";
+
+const UA = { "User-Agent": "leonida-assets/0.1 (local hobby project)" };
+const SLUGS = ["asphalt_02", "concrete_pavement_03", "white_stucco", "sand_01", "leafy_grass", "grass_path_2", "palm_bark"];
+const MAPS = ["Diffuse", "nor_gl", "arm"];
+
+await mkdir("public/textures", { recursive: true });
+for (const slug of SLUGS) {
+    const files = await (await fetch(`https://api.polyhaven.com/files/${slug}`, { headers: UA })).json();
+    for (const map of MAPS) {
+        const entry = files[map]?.["1k"]?.jpg;
+        if (!entry) { console.warn(`${slug}: ${map} fehlt`); continue; }
+        const buf = Buffer.from(await (await fetch(entry.url, { headers: UA })).arrayBuffer());
+        await writeFile(`public/textures/${slug}_${map}.jpg`, buf);
+        console.log(`${slug}_${map}.jpg ${(buf.length / 1e6).toFixed(1)} MB`);
+    }
+}