feat: sync showcase with WRNexusJS 0.8.72 and @wrnexus/ui 0.8.88

- Sync app, public, scripts, test and examples from the framework's
  component-showcase: redesigned component demos, marketing blocks under
  /blocks, template and preview galleries, distinct Timeline/Section
  variants, Chat Bubble receipts, a top-placement Drawer demo, and the
  playground code panel fix (objects in array props no longer blank out).
- Standalone adaptations kept: the generator and tests read
  component-reference.json from the published @wrnexus/ui, and tests use
  the published @wrnexus/compiler and @wrnexus/syntax.
- Dependencies: every @wrnexus/* package to its latest release (ui 0.8.88,
  styles 0.8.26, core 0.8.16, cli 0.8.72, ...), happy-dom for the
  playground tests, Tailwind 4.3; bun.lock and package-lock.json refreshed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/showcase-images/office-map.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 800 440"><rect width="800" height="440" fill="#e8ece8"/><g fill="#fafbf9" stroke="#a5b5ae" stroke-width="4"><rect x="50" y="40" width="220" height="150" rx="12"/><rect x="330" y="40" width="180" height="150" rx="12"/><rect x="570" y="40" width="180" height="360" rx="12"/><rect x="50" y="250" width="220" height="150" rx="12"/><rect x="330" y="250" width="180" height="150" rx="12"/></g><path d="M25 220H550V420M300 20V420" stroke="#bccdc4" stroke-width="22" fill="none"/><g fill="#496258" font-family="sans-serif" font-size="16" text-anchor="middle"><text x="160" y="165">Design studio</text><text x="420" y="165">Meeting room</text><text x="660" y="365">Shared workspace</text><text x="160" y="370">Reception</text><text x="420" y="370">Kitchen</text></g></svg>