Build an Engine application

Read package.json and the entry point, keep the surface that owns the lifecycle, and read only its reference: direct Engine, React, or Web Components. Choose from imports and markup, not dependencies.

Bootstrap

• Input is opt-in. app.keyboard, mouse, touch, gamepads, and elementInput stay null unless passed to new Application(canvas, { ... }); UI buttons need new ElementInput(canvas).
• The Engine adds no window resize listener; call app.resizeCanvas() from your own handler.
• graphicsDevice.maxPixelRatio defaults to 1. Raise it, at most to window.devicePixelRatio, only where the target holds its frame budget, call app.resizeCanvas(), and confirm with canvas.width / canvas.clientWidth.
• Rigid bodies stay inert until Ammo loads through WasmModule. Copy the loader from the physics/falling-shapes example with find-examples.
• devtools defaults to true, so debugging tools can find the app (inspect-runtime). Set it to false only to hide a production build.