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/joomla.asset.json

@@ -17,7 +17,7 @@
 			"defgroup": "Joomla.Template.Site",
 			"ingroup": "MokoCassiopeia.Template.Assets",
 			"path": "./media/templates/site/mokocassiopeia/joomla.asset.json",
-			"version": "03.09.15",
+			"version": "03.09.16",
 			"brief": "Joomla asset registry for MokoCassiopeia"
 		}
 	},