feat(inventory): add traceable cart stock reservations

app/Domains/Cart/Models/CartItem.php

@@ -3,11 +3,13 @@
 namespace App\Domains\Cart\Models;
 
 use App\Domains\Catalog\Models\CatalogItem;
+use App\Domains\Catalog\Models\StockReservation;
 use App\Domains\Catalog\Models\Variant;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 
 #[Fillable([
     'cart_id',
@@ -55,4 +57,10 @@ class CartItem extends Model
     {
         return $this->variant ?? $this->catalogItem;
     }
+
+    /** @return HasMany<StockReservation, $this> */
+    public function stockReservations(): HasMany
+    {
+        return $this->hasMany(StockReservation::class);
+    }
 }