# WASM build — placeholder

Phase 0 task **"WASM hello-world build (Emscripten)"** and the Phase 2 task
**"WASM rendering path"** live here. Not implemented yet.

**Rule R5: WASM never blocks shipping.** Server-side rendering is always the
fallback. The Phase 0 WASM task is *validation only* — prove that Emscripten can
compile a C++ function callable from JS. Do not gate Phase 1 on it.

Planned pipeline (engine blueprint §6):

```sh
emcmake cmake --preset wasm
emmake cmake --build --preset wasm
# outputs: engine.wasm + engine.js
```

Key build flags to carry forward: `ALLOW_MEMORY_GROWTH=1`, Web Worker +
OffscreenCanvas for off-main-thread rendering.

The `cmake/toolchains/wasm.cmake` hook and a `wasm` CMake preset are stubbed in
this session so the integration point exists.