feat(ui-polish): sidebar icons + topbar + dashboard redesign
- Sidebar: lucide-react icons, lock on gated items, upgrade badge on "Mon plan", user footer with avatar initials + plan label, "EX|PRIA" logo header
- Topbar: sticky with backdrop-blur, breadcrumb via centralized route-titles.ts, search placeholder, keyboard shortcuts + notifications icons
- Dashboard: split into Free/Standard/Premium views (ARCHITECTURE.md §3 aligned)
- NclcHero: NCLC display + gauge 5→10 + SVG score ring
- StatCards: simulations remaining + NCLC estimé + dernier score with delta
- RecentSimulations: 3 latest with NCLC badge + chevron nav
- NextStepCard: static recommendation per plan
- PaywallBanner: full-width redesign + fixed dead Boréal tokens
- Removed orphan MobileHeader.tsx (0 consumers)
Typecheck: OK · Tests: 122/122 ✅
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Hermann_Kitio
4005673ae8