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/types.ts

@@ -0,0 +1,30 @@
+/**
+ * Public TypeScript surface for @valknar/vpinball-wasm.
+ *
+ * This wraps the raw Emscripten-generated module (dist/vpinball.js) so
+ * consumers don't need to know about ccall/cwrap/FS internals directly.
+ */
+
+export interface LoadPinballOptions {
+	/** Canvas the engine renders into via SDL3's WebGL2 backend. */
+	canvas: HTMLCanvasElement;
+	/**
+	 * Raw bytes of a .vpx table file to load on startup. If omitted, the
+	 * bundled default table (package/assets/test000-default-table.vpx) is
+	 * used instead.
+	 */
+	tableData?: ArrayBuffer;
+	/** Base URL to fetch dist/vpinball.wasm (and .data, if present) from. */
+	baseUrl?: string;
+}
+
+export interface PinballInstance {
+	/** Load a different .vpx table at runtime, replacing the current one. */
+	loadTable(vpxBytes: ArrayBuffer): void;
+	/** Start (or resume) the simulation's main loop. */
+	start(): void;
+	/** Pause the simulation's main loop. */
+	stop(): void;
+	/** Tear down the instance and free its WebAssembly memory. */
+	dispose(): void;
+}