feat: clean credits users

app/Models/BillingProduct.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace App\Models;
+
+use App\Enums\BillingProductPurpose;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Concerns\HasUlids;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\HasMany;
+
+class BillingProduct extends Model
+{
+    use HasFactory, HasUlids;
+
+    protected $fillable = [
+        'name',
+        'description',
+        'purpose',
+        'amount',
+        'currency',
+        'stripe_product_id',
+        'stripe_price_id',
+        'is_active',
+        'sort_order',
+    ];
+
+    public function paymentTransactions(): HasMany
+    {
+        return $this->hasMany(PaymentTransaction::class);
+    }
+
+    public function scopeActive(Builder $query): Builder
+    {
+        return $query->where('is_active', true);
+    }
+
+    public function formattedAmount(): string
+    {
+        return number_format($this->amount / 100, 2, ',', ' ').' '.strtoupper($this->currency);
+    }
+
+    protected function casts(): array
+    {
+        return [
+            'purpose' => BillingProductPurpose::class,
+            'amount' => 'integer',
+            'is_active' => 'boolean',
+            'sort_order' => 'integer',
+        ];
+    }
+}