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>

app/pages/preview/project-board.wrn

@@ -0,0 +1,7 @@
+page ProjectBoardExample {
+ state tasks = [{label:"Review designs"},{label:"Build the dashboard"},{label:"Test accessibility"}]
+ view {
+<nav class="example-toolbar"><a href="/preview">← All examples</a><a href="#example-source">View code</a></nav> <main class="example-form-page" style="max-width:42rem;margin:3rem auto;padding:1.5rem;display:grid;gap:1.5rem"><h1>Project workspace</h1><DragAndDrop title="Priorities" description="Drag a row or use its arrow buttons." items="{tasks}" /><WysiwygEditor title="Team update" value="Share what you are working on this week." /></main> <section class="example-code-panel"><header><h2>Copy this example</h2><button type="button" data-copy-target="#example-source">Copy code</button></header><pre><code id="example-source">page ProjectBoardExample <span>&#123;</span>
+ state tasks = [<span>&#123;</span>label:"Review designs"<span>&#125;</span>,<span>&#123;</span>label:"Build the dashboard"<span>&#125;</span>,<span>&#123;</span>label:"Test accessibility"<span>&#125;</span>]
+ view <span>&#123;</span> &lt;main class="example-form-page" style="max-width:42rem;margin:3rem auto;padding:1.5rem;display:grid;gap:1.5rem"&gt;&lt;h1&gt;Project workspace&lt;/h1&gt;&lt;DragAndDrop title="Priorities" description="Drag a row or use its arrow buttons." items="<span>&#123;</span>tasks<span>&#125;</span>" /&gt;&lt;WysiwygEditor title="Team update" value="Share what you are working on this week." /&gt;&lt;/main&gt; <span>&#125;</span>
+<span>&#125;</span></code></pre></section> } }