create crud product categories and partial update crud products with dealers stock

app/Models/Dealer.php

@@ -22,4 +22,10 @@ class Dealer extends Model
     {
         return $this->hasMany(Transaction::class, 'dealer_id', 'id');
     }
+
+    public function products(){
+        return $this->belongsToMany(Product::class, 'stock')
+        ->withPivot('quantity')
+        ->withTimestamps();
+    }
 }