Add saved firewall configuration functionality

- Implemented the ability to save, view, apply, and delete firewall configurations for users.
- Created a new model for FirewallConfiguration and corresponding database migration.
- Enhanced the firewall view to include a tab for managing saved configurations.

extensions/Servers/Proxmox/Models/FirewallConfiguration.php

@@ -0,0 +1,50 @@
+<?php
+
+namespace Paymenter\Extensions\Servers\Proxmox\Models;
+
+use App\Models\User;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class FirewallConfiguration extends Model
+{
+    protected $table = 'ext_proxmox_firewall_configurations';
+
+    protected $fillable = [
+        'user_id',
+        'configuration_name',
+        'firewall_rules',
+        'incoming_policy',
+        'outgoing_policy',
+    ];
+
+    protected $casts = [
+        'firewall_rules' => 'array',
+        'created_at' => 'datetime',
+        'updated_at' => 'datetime',
+    ];
+
+    /**
+     * Get the user that owns this firewall configuration.
+     */
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
+
+    /**
+     * Scope a query to only include configurations for a specific user.
+     */
+    public function scopeForUser($query, int $userId)
+    {
+        return $query->where('user_id', $userId);
+    }
+
+    /**
+     * Get the rules count for display.
+     */
+    public function getRulesCountAttribute(): int
+    {
+        return is_array($this->firewall_rules) ? count($this->firewall_rules) : 0;
+    }
+}