Add production www layout for levkin.ca hosting.

- build:www maps / to spec and /folders to stack-folder
- Umami tracking via stats.levkin.ca
- nginx deploy config for site LXC

Co-authored-by: Cursor <cursoragent@cursor.com>

stack-folder/index.html

@@ -61,7 +61,7 @@
           <h2>Scope</h2>
           <p><span class="hi">Boutique practice</span> — not a staffing agency. Clear deliverable and handoff so your team can own what ships.</p>
         </div>
-        <a class="site-preview" href="/spec/" target="_blank" rel="noopener noreferrer">
+        <a class="site-preview" href="/" target="_blank" rel="noopener noreferrer">
           <span class="site-preview-bar"><span class="site-preview-url">levkin.ca / spec</span><span class="site-preview-go" aria-hidden="true">↗</span></span>
           <span class="site-preview-frame"><img class="site-preview-img" src="./previews/spec.png" alt="" loading="lazy" decoding="async" /></span>
         </a>