Add vpinball: a browser Visual Pinball player

Next.js app that plays real .vpx tables via @valknar/vpinball-wasm
(WebAssembly Visual Pinball). Demo mode with the bundled default
table, drag-and-drop custom table upload, a cabinet-styled UI with a
coin-door HUD (fullscreen/stats/info/eject), a custom 404 page, PWA
support (hand-rolled service worker), and a static Docker Compose
deployment behind nginx.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012hQoM3jJT1Lx7CMTciMzvD

lib/pinball/webglSupport.ts

@@ -0,0 +1,9 @@
+export function hasWebGL2(): boolean {
+  if (typeof window === "undefined") return false;
+  try {
+    const canvas = document.createElement("canvas");
+    return Boolean(canvas.getContext("webgl2"));
+  } catch {
+    return false;
+  }
+}