fix: Adjust stock opname logic to apply the difference between physical and system quantities to the current stock.

app/Livewire/Studio/Stock/StockOpname/Index.php

@@ -74,20 +74,26 @@ public function approveApproval(StockOpname $stockOpname): void
                     ->where($itemable->getTable().'.id', $itemable->id)
                     ->first();
 
+                // Current stock is the stock of the item in the outlet at the time the stock opname was created
                 $currentStock = $currentPivot?->pivot?->stock ?? 0;
 
-                $quantity = $item->qty_physical;
+                // Calculate the difference between the physical stock and the system stock AT THE TIME the stock opname was created
+                // then apply the difference to the current stock
+                // Example: qty_system=100, qty_physical=90, transaction 20 occurred
+                // currentStock=80, difference=-10, newStock=80+(-10)=70 ✓
+                $difference = $item->qty_physical - $item->qty_system;
+                $newStock = max(0, $currentStock + $difference);
 
                 $outlet->$relationName()->syncWithoutDetaching([
-                    $itemable->id => ['stock' => $quantity],
+                    $itemable->id => ['stock' => $newStock],
                 ]);
 
                 StockActivityLogService::stockOpname(
                     stockOpname: $stockOpname,
                     product: $itemable,
-                    quantityChange: $quantity - $currentStock,
+                    quantityChange: $newStock - $currentStock,
                     previousStock: $currentStock,
-                    newStock: $quantity,
+                    newStock: $newStock,
                     note: $stockOpname->note
                 );
             }