Scaffold vpinball-wasm: Emscripten port of Visual Pinball

Build scripts, CMake/source patches, npm packaging, and a Gitea CI
workflow to compile the real Visual Pinball engine (SDL3 + WebGL2 +
libwinevbs for real VBScript) to WebAssembly.

The patches are validated end-to-end: the patched engine boots in a
real browser, loads a real .vpx table, compiles its real GLSL shaders,
computes environment map radiance, initializes physics, and starts the
VBScript engine, before hanging on the one deliberately-deferred piece
of work (game loop rewrite around emscripten_set_main_loop), documented
in the README's roadmap.

package/src/index.ts

@@ -0,0 +1,59 @@
+import type { LoadPinballOptions, PinballInstance } from './types.js';
+
+export type { LoadPinballOptions, PinballInstance } from './types.js';
+
+/**
+ * Instantiates the WebAssembly build of Visual Pinball against the given
+ * canvas.
+ *
+ * NOTE (current milestone): this wrapper boots the Emscripten module and
+ * exposes lifecycle control (start/stop/dispose). Runtime table loading
+ * (`loadTable`) mounts the given bytes into the module's virtual filesystem,
+ * but wiring the native engine to actually pick up a runtime-loaded table
+ * (as opposed to the table baked in at build time) is tracked as a follow-up
+ * milestone in the README's roadmap - see "Browser file-loading UX".
+ */
+export async function loadPinball(options: LoadPinballOptions): Promise<PinballInstance> {
+	const baseUrl = options.baseUrl ?? '.';
+
+	// dist/vpinball.js is built with -sMODULARIZE=1 -sEXPORT_NAME=VPinballModule,
+	// so importing it yields a factory function, not a module with side effects.
+	const factory = (await import(/* @vite-ignore */ `${baseUrl}/vpinball.js`)).default as (
+		moduleArgs: Record<string, unknown>
+	) => Promise<EmscriptenModule>;
+
+	const module = await factory({
+		canvas: options.canvas,
+		locateFile: (path: string) => `${baseUrl}/${path}`,
+	});
+
+	if (options.tableData) {
+		mountTable(module, options.tableData);
+	}
+
+	return {
+		loadTable(vpxBytes: ArrayBuffer) {
+			mountTable(module, vpxBytes);
+		},
+		start() {
+			module.ccall?.('vpinball_wasm_start', null, [], []);
+		},
+		stop() {
+			module.ccall?.('vpinball_wasm_stop', null, [], []);
+		},
+		dispose() {
+			module.ccall?.('vpinball_wasm_dispose', null, [], []);
+		},
+	};
+}
+
+function mountTable(module: EmscriptenModule, vpxBytes: ArrayBuffer): void {
+	module.FS.writeFile('/table.vpx', new Uint8Array(vpxBytes));
+}
+
+interface EmscriptenModule {
+	FS: {
+		writeFile(path: string, data: Uint8Array): void;
+	};
+	ccall?: (name: string, returnType: string | null, argTypes: string[], args: unknown[]) => unknown;
+}