Adds a whole-app visual-register switch, orthogonal to the light/dark
toggle and accent color, via a new [data-look] token layer in index.css:
- Enterprise (default): unchanged clean SaaS baseline.
- Proxmox-native: utilitarian and dense — plain system font, smaller root
scale, zero radius, no shadows, flat bordered panels.
- Terminal: quiet and precise — the whole UI (not just data) sets in
monospace, no display face, flat near-zero-radius panels.
Persisted server-side alongside theme/accent (new `look` column on
user_preferences, migration 00008) with a live-scoped preview per option
in Settings > Appearance.
Anand