[FIX] 修正採購單大單位換算問題並建立 Git 開發規範

app/Modules/Inventory/Services/GoodsReceiptService.php

@@ -266,10 +266,24 @@ class GoodsReceiptService implements \App\Modules\Inventory\Contracts\GoodsRecei
                     default => '進貨入庫',
                 };
 
+                $quantityToRecord = $grItem->quantity_received;
+                
+                // 單位換算邏輯：僅針對標準採購且有連結 PO Item 時
+                if ($goodsReceipt->type === 'standard' && $grItem->purchase_order_item_id) {
+                    $poItem = \App\Modules\Procurement\Models\PurchaseOrderItem::find($grItem->purchase_order_item_id);
+                    $product = $this->inventoryService->getProduct($grItem->product_id);
+                    
+                    if ($poItem && $product && $poItem->unit_id && $product->large_unit_id && $poItem->unit_id == $product->large_unit_id) {
+                        // 如果使用的是大單位，則換算為基本單位數量
+                        $quantityToRecord = $grItem->quantity_received * ($product->conversion_rate ?: 1);
+                        Log::info("Goods Receipt [{$goodsReceipt->code}] converted quantity for product [{$product->id}]: {$grItem->quantity_received} large unit -> {$quantityToRecord} base unit.");
+                    }
+                }
+
                 $this->inventoryService->createInventoryRecord([
                     'warehouse_id' => $goodsReceipt->warehouse_id,
                     'product_id' => $grItem->product_id,
-                    'quantity' => $grItem->quantity_received,
+                    'quantity' => $quantityToRecord,
                     'unit_cost' => $grItem->unit_price,
                     'batch_number' => $grItem->batch_number,
                     'expiry_date' => $grItem->expiry_date,
@@ -282,6 +296,7 @@ class GoodsReceiptService implements \App\Modules\Inventory\Contracts\GoodsRecei
 
                 // 2. Update PO if linked and type is standard
                 if ($goodsReceipt->type === 'standard' && $goodsReceipt->purchase_order_id && $grItem->purchase_order_item_id) {
+                    // 更新採購單的實收數量 (維持原始單位數量，以便與採購數量比較)
                     $this->procurementService->updateReceivedQuantity(
                         $grItem->purchase_order_item_id,
                         $grItem->quantity_received