chore: remove dead code, unused CSS, unused components, and clean up git tracking

- Remove storage/logs/ and prod.log from git tracking; add to .gitignore
- Remove unused AvatarCarousel and ArticleSlider components
- Remove unused SkeletonTable export from ui.tsx
- Remove unused ChevronDown import from admin layout
- Remove 13 unused CSS classes (icon-base, nav-*, navigation-icon*, .app.dark,
  text-body, transition-base, card-base, admin-info-grid, .coin.*)
- Remove duplicate translation keys (openMenu/closeMenu in en.json)
- Fix admin-bans to use Prisma-generated bans_type enum
- Create shared AdminPageHeader component and formatDate utility
- Add logger and generateRequestId for structured logging
- All 58 tests pass, typecheck clean, build succeeds

src/messages/en.json

@@ -21,9 +21,7 @@
     "admin": "Admin",
     "openMenu": "Open menu",
     "closeMenu": "Close menu",
-    "drawBadge": "Draw badge",
-    "openMenu": "Open menu",
-    "closeMenu": "Close menu"
+    "drawBadge": "Draw badge"
   },
   "header": {
     "online": "{count} {hotel} online",