v03.09.16: brand-aside columns, offline page redesign, variable click-to-copy

- Brand-aside position now uses flex columns like top-a (card style, equal-width)
- Offline page: external offline.css with theme variables, 3-column centered card
  layout, Osaka font loading, full-screen on mobile
- CSS variable click-to-copy: scans text for --var patterns, wraps in clickable
  chips with toast notification on copy
- Search button border matches input border (--input-border-color)
- mod_stats override: converted from dl to table layout
- Patch bump 03.09.15 → 03.09.16

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/index.php

@@ -406,7 +406,7 @@ $wa->useScript('user.js');         // js/user.js
 				</div>
 				<?php if ($this->countModules('brand-aside', true)) : ?>
 					<div class="container-brand-aside">
-						<jdoc:include type="modules" name="brand-aside" style="none" />
+						<jdoc:include type="modules" name="brand-aside" style="card" />
 					</div>
 				<?php endif; ?>
 			</div>