Fix 40+ codebase issues: security, performance, duplication, dead code, and routes

HIGH:
- Add missing import RadioSongRequestFormRequest (fixes crash on POST)
- Add Purify XSS sanitization for article full_story
- Fix duplicate radio API routes (/api/radio vs /api/radio/v2)
- Add try-catch guards in InstallationController for missing records

MEDIUM:
- Fix N+1: eager load comments.user in ArticleController::show()
- Fix GuestbookController authorization logic
- Remove dead doSetup() method and duplicate route
- Extract shared HasRadioDefaults trait (remove code duplication)
- Use named routes in ForceStaffTwoFactorMiddleware
- Fix WebsiteHelpCenterTicket::isOpen() (no permission leak)
- Enable  on WebsiteHelpCenterTicket (matches schema)
- Replace WebsiteTeam::all()->pluck() with direct pluck()
- Replace CatalogPage::all()->pluck() with direct pluck()
- Replace WebsiteBadge::all() with direct pluck()
- Add throttle middleware to guestbook store, logo-generator, radio embed

LOW:
- Remove unused imports
- Remove dead /inertia-test route
- Consolidate cache keys in RadioController

app/Http/Controllers/Concerns/HasRadioDefaults.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace App\Http\Controllers\Concerns;
+
+use App\Models\Miscellaneous\WebsiteSetting;
+use App\Models\RadioRank;
+
+trait HasRadioDefaults
+{
+    private function createDefaultRanks(): void
+    {
+        $ranks = [
+            ['name' => 'Trainee DJ', 'level' => 1, 'is_active' => true, 'description' => 'Beginnende DJ'],
+            ['name' => 'Junior DJ', 'level' => 2, 'is_active' => true, 'description' => 'Ervaren DJ'],
+            ['name' => 'Senior DJ', 'level' => 3, 'is_active' => true, 'description' => 'Professionele DJ'],
+            ['name' => 'Head DJ', 'level' => 4, 'is_active' => true, 'description' => 'Hoofd DJ'],
+            ['name' => 'Radio Manager', 'level' => 5, 'is_active' => true, 'description' => 'Radio Manager'],
+        ];
+
+        foreach ($ranks as $rank) {
+            RadioRank::updateOrCreate(
+                ['name' => $rank['name']],
+                $rank,
+            );
+        }
+    }
+
+    private function saveRadioSettings(array $settings): void
+    {
+        foreach ($settings as $key => $value) {
+            WebsiteSetting::updateOrCreate(
+                ['key' => $key],
+                ['value' => (string) $value, 'comment' => 'Radio setting'],
+            );
+        }
+    }
+}