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>

README.md

@@ -9,7 +9,7 @@
  INGROUP: MokoCassiopeia.Documentation
  REPO: https://git.mokoconsulting.tech/MokoConsulting/MokoCassiopeia
  FILE: ./README.md
- VERSION: 03.09.15
+ VERSION: 03.09.16
  BRIEF: Documentation for MokoCassiopeia template
  -->