render3d im Browser: WASM/WebGPU-3D-Viewport hinter ?engine=wasm

Feature web (wasm-bindgen) + cdylib analog render2d; WebModelRenderer
mit Canvas-Surface, set_model (walls/slabs wie der native Push) und
set_camera. Projektion liefert bereits [0,1]-Clip-Z, math.rs unveraendert.
wgpu-22-requestDevice-Shim in src/engine/requestDeviceShim.ts geteilt.
Neuer Hook useWasm3dRenderer + Wasm3DViewport (Orbit/Pan/Zoom wie three.js-
Sicht); Viewport3D dispatcht per ?engine=wasm bzw. localStorage, three.js
bleibt Default. Build-Script build:engine3d (wasm-pack, src/engine/pkg3d).
Verifiziert headful per scripts/probe-engine3d.mjs (37 % Geometrie-Pixel);
headless praesentiert Chromium keine WebGPU-Frames (auch bei render2d).

package.json

@@ -15,7 +15,8 @@
     "dump:native": "node scripts/dump-native-scene.mjs",
     "shell": "scripts/chromium-shell.sh",
     "electron": "scripts/electron-shell.sh",
-    "build:engine": "wasm-pack build src-tauri/render2d --release --target web --out-dir ../../src/engine/pkg --out-name render2d --no-default-features --features web"
+    "build:engine": "wasm-pack build src-tauri/render2d --release --target web --out-dir ../../src/engine/pkg --out-name render2d --no-default-features --features web",
+    "build:engine3d": "wasm-pack build src-tauri/render3d --release --target web --out-dir ../../src/engine/pkg3d --out-name render3d --no-default-features --features web"
   },
   "dependencies": {
     "@mlightcad/libredwg-web": "^0.7.7",