v2.5.0 — Addon System, Vacay, Atlas, Dashboard Widgets & Mobile Overhaul

The biggest NOMAD update yet. Introduces a modular addon architecture and three major new features.

Addon System:
- Admin panel addon management with enable/disable toggles
- Trip addons (Packing List, Budget, Documents) dynamically show/hide in trip tabs
- Global addons appear in the main navigation for all users

Vacay — Vacation Day Planner (Global Addon):
- Monthly calendar view with international public holidays (100+ countries via Nager.Date API)
- Company holidays with auto-cleanup of conflicting entries
- User-based system: each NOMAD user is a person in the calendar
- Fusion system: invite other users to share a combined calendar with real-time WebSocket sync
- Vacation entitlement tracking with automatic carry-over to next year
- Full settings: block weekends, public holidays, company holidays, carry-over toggle
- Invite/accept/decline flow with forced confirmation modal
- Color management per user with collision detection on fusion
- Dissolve fusion with preserved entries

Atlas — Travel World Map (Global Addon):
- Fullscreen Leaflet world map with colored country polygons (GeoJSON)
- Glass-effect bottom panel with stats, continent breakdown, streak tracking
- Country tooltips with trip count, places visited, first/last visit dates
- Liquid glass hover effect on the stats panel
- Canvas renderer with tile preloading for maximum performance
- Responsive: mobile stats bars, no zoom controls on touch

Dashboard Widgets:
- Currency converter with 50 currencies, CustomSelect dropdowns, localStorage persistence
- Timezone widget with customizable city list, live updating clock
- Per-user toggle via settings button, bottom sheet on mobile

Admin Panel:
- Consistent dark mode across all tabs (CSS variable overrides)
- Online/offline status badges on user list via WebSocket
- Unified heading sizes and subtitles across all sections
- Responsive tab grid on mobile

Mobile Improvements:
- Vacay: slide-in sidebar drawer, floating toolbar, responsive calendar grid
- Atlas: top/bottom glass stat bars, no popups
- Trip Planner: fixed position content container prevents overscroll, portal-based sidebar buttons
- Dashboard: fixed viewport container, mobile widget bottom sheet
- Admin: responsive tab grid, compact buttons
- Global: overscroll-behavior fixes, modal scroll containment

Other:
- Trip tab labels: Planung→Karte, Packliste→Liste, Buchungen→Buchung (DE mobile)
- Reservation form responsive layout
- Backup panel responsive buttons

client/src/components/Admin/CategoryManager.jsx

@@ -190,13 +190,14 @@ export default function CategoryManager() {
     <div className="bg-white rounded-2xl border border-gray-200 p-6">
       <div className="flex items-center justify-between mb-6">
         <div>
-          <h2 className="text-lg font-semibold text-gray-900">{t('categories.title')}</h2>
-          <p className="text-sm text-gray-500 mt-0.5">{t('categories.subtitle')}</p>
+          <h2 className="font-semibold" style={{ color: 'var(--text-primary)' }}>{t('categories.title')}</h2>
+          <p className="text-xs mt-1" style={{ color: 'var(--text-muted)' }}>{t('categories.subtitle')}</p>
         </div>
         <button onClick={handleStartCreate}
-          className="flex items-center gap-2 bg-slate-900 text-white px-4 py-2 rounded-lg hover:bg-slate-700 text-sm font-medium">
+          className="flex items-center gap-2 bg-slate-900 text-white px-3 sm:px-4 py-2 rounded-lg hover:bg-slate-700 text-sm font-medium">
           <Plus className="w-4 h-4" />
-          {t('categories.new')}
+          <span className="hidden sm:inline">{t('categories.new')}</span>
+          <span className="sm:hidden">Add</span>
         </button>
       </div>