Fix security, performance, and code quality issues across CMS

Security:
- Replace unescaped {!! !!} with Purify::clean() in 15+ Blade templates (XSS)
- Add rate limiting to register (3/hr), upload (10/min), SSE (6/min)
- Add max:5000 validation on article comments
- Remove duplicate exception handler callback

Hardcoded paths:
- Replace ~44 /var/www/ hardcoded paths with env() configs
- CatalogService (13), AutoDetectService (18), Commandocentrum (11), AppServiceProvider (2)

Performance:
- Add 10 missing database indexes (radio_song_requests, help_center_tickets, etc.)
- Replace Cache::flush() with targeted Cache::forget() in RadioSettings
- Cache getCachedCategories() in TicketController (N+1 fix)
- Remove redundant top-3 leaderboard query

Bug fixes:
- Fix undefined $enabled variable → $isOnline in radio index view
- Add getAvatarAttribute() accessor for non-existent avatar column
- Fix User::guilds() from wrong HasMany to HasManyThrough

Code quality:
- Replace file_get_contents with Http::timeout(10) in TraxService
- Remove commented Echo/Pusher boilerplate in bootstrap.js
- Remove TODO/FIXME comments from logo-generator templates
- Replace hardcoded Turnstile CDN URL with config()
- Restore QUEUE_CONNECTION=redis in .env.example files

resources/themes/dusk/views/help-center/tickets/show.blade.php

@@ -48,7 +48,7 @@
         </div>
 
         <article class="prose-xl mt-8" style="width: 100%;">
-            {!! $ticket->content !!}
+            {{ \Stevebauman\Purify\Facades\Purify::clean($ticket->content) }}
         </article>
     </x-content.content-card>
 
@@ -140,7 +140,7 @@
                         </div>
 
                         <div class="p-4">
-                            {!! $reply->content !!}
+                            {{ \Stevebauman\Purify\Facades\Purify::clean($reply->content) }}
                         </div>
                     </div>
                 @else
@@ -171,7 +171,7 @@
                         </div>
 
                         <div class="p-4">
-                            {!! $reply->content !!}
+                            {{ \Stevebauman\Purify\Facades\Purify::clean($reply->content) }}
                         </div>
                     </div>
                 @endif