feat(website): brand guide page + NodeMark/NodeLockup variants

Replace the /brand stub with the full Brand Guide from the Claude Design
handoff (cover, logo, color, typography, voice, applications), rendered inside
the site layout, English-only, with illustrative copy adapted to Dezky's real
EU-sovereign voice. Extend NodeMark with a `variant` (donut/solid/outline) and
NodeLockup with a separate `wordmark` colour so the mark reads correctly on
dark surfaces. Drops the old brand stub copy.

apps/website/components/brand/NodeLockup.vue

@@ -7,6 +7,10 @@ const props = withDefaults(defineProps<{
   scale?: number
   fg?: string
   accent?: string
+  // Wordmark colour. Defaults to `fg`; pass separately when the squircle and
+  // the wordmark need different colours (e.g. on a dark surface the squircle is
+  // carbon — invisible — while the wordmark must stay light).
+  wordmark?: string
 }>(), {
   scale: 1,
   fg: C.carbon,
@@ -22,7 +26,7 @@ const props = withDefaults(defineProps<{
       fontWeight: 600,
       fontSize: `${56 * scale * 0.78}px`,
       letterSpacing: '-0.04em',
-      color: fg,
+      color: wordmark || fg,
       lineHeight: 0.9,
     }">dezky</span>
   </div>