Add self-contained vanilla HTML port of the wizard

A single-file (no build step, no dependencies) port of the whole app,
living alongside the existing React/Vite SPA without touching it.

- standalone-html/index.html: all CSS/JS inlined, zero external
  requests (no CDN scripts/fonts, no fetch/XHR), works via file://
  or any static host
- Engine (assess()/buildRecommendations()) ported byte-identical to
  src/logic/engine.js; verified against the live React app with a
  fresh answer combination and got identical governance tier, gateway
  tier, score, and escalations
- Decision-tree diagram, modal (scroll-lock/Escape/backdrop-click),
  and all wizard/landing/results views reproduced with the same
  look and feel
- Text-input keystrokes patch only the Next button/progress dot
  instead of a full re-render, so focus/cursor position is preserved
  while typing

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: vijaydixitffis

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 dist
+.DS_Store