Add semantic design tokens and base primitives to replace the verbose
inline var() styling that made the UI feel dated.
- Rename colliding Tailwind color tokens (bg-primary/bg-secondary) to
semantic names (surface/surface-raised/content/content-muted/brand/line)
- Derive hover, overlay, border-strong, accent-muted and elevation tokens
once on <body> so they adapt to every theme automatically
- Make :root mirror Tokyo Night to kill the first-paint theme flash
- Add component primitives in @layer components: .card (surface + soft
shadow, no hard border), .btn variants, .input, .chip, .badge, .icon-btn
- Add theme-aware status/priority badges and global focus-visible styling
- Add an inline-SVG Icon() component (consistent stroke language) to
replace the mixed emoji/SVG iconography
- Data-drive theme/wood options and add an active-nav helper
- Add skeleton shimmer + x-cloak support
