Add NAS file manager integration and all pending platform changes

- Installed p7h/nas-file-manager package via private VCS repo
- Published config/nas-file-manager.php with super_admin middleware restriction
- Added NAS env vars to .env.example
- Created admin/nas-storage page with connection info panel and file browser widget
- Added NAS Storage link to admin sidebar (super_admin only)
- Added SuperAdminController@nasStorage method and admin.nas-storage route
- Includes all accumulated branch changes: profile wall, 2FA, audit logs,
  settings panel, country/phone/timezone components, posts, slideshow,
  playlist shares, video downloads/shares, comment likes, notifications,
  social links, and more

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

app/Models/VideoSlide.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class VideoSlide extends Model
+{
+    protected $fillable = ['video_id', 'filename', 'position'];
+
+    public function video()
+    {
+        return $this->belongsTo(Video::class);
+    }
+
+    public function getUrlAttribute(): string
+    {
+        return asset('storage/thumbnails/' . $this->filename);
+    }
+}