feat: rebuild desktop UI to match Figma + website, hero slider improvements

- Desktop sidebar (262px, blue gradient, white pill nav), topbar (search + bell + avatar), responsive shell rewritten
- Desktop homepage: immersive hero with Ken Burns animation, pill category chips, date badge cards matching mvnew.eventifyplus.com/home
- Desktop calendar: 60/40 two-column layout with white background
- Desktop profile: full-width banner + 3-column event grids
- Desktop learn more: hero image + about/venue columns + gallery strip
- Desktop settings/contribute: polished to match design system
- Mobile hero slider: RepaintBoundary, animated dots with 44px tap targets, 5s auto-scroll, 8s post-swipe delay, shimmer loading, dynamic event type badge, human-readable dates
- Guest access: requiresAuth false on read endpoints
- Location fix: show place names instead of lat/lng coordinates
- Version 1.6.1+17

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

lib/screens/search_screen.dart

@@ -149,7 +149,7 @@ class _SearchScreenState extends State<SearchScreen> {
         }
       } catch (_) {}
 
-      if (mounted) Navigator.of(context).pop('${pos.latitude.toStringAsFixed(5)},${pos.longitude.toStringAsFixed(5)}');
+      if (mounted) Navigator.of(context).pop('Current Location');
     } catch (e) {
       if (mounted) {
         ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Could not determine location: $e')));