Add formula-based product pricing (P/W/MG) for Parsian-style unit prices.

Port FormulaPriceService from colleague app so admins can compute a single unit price from reference mid, weight, and wage instead of offset coefficients.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/Services/ProductPriceService.php

@@ -78,6 +78,45 @@ class ProductPriceService
             return null;
         }
 
+        if (FormulaPriceService::isEnabled($product)) {
+            $computed = FormulaPriceService::calculateForProduct($product, [
+                'price' => $basePrice,
+                'active' => true,
+            ]);
+
+            if ($computed === null || $computed <= 0) {
+                if (
+                    Product::hasUseLastPriceIfZeroColumn()
+                    && ($product->use_last_price_if_zero ?? false)
+                ) {
+                    return null;
+                }
+
+                $computed = 0;
+            }
+
+            $oldPrice = (int) ($product->price ?? 0);
+            $data = ['price' => $computed];
+            if (\Illuminate\Support\Facades\Schema::hasColumn($product->getTable(), 'price_profit')) {
+                $data['price_profit'] = 0;
+            }
+            Product::where('id', $product->id)->update($data);
+
+            return [
+                'product_id' => $product->id,
+                'product_title' => $product->title,
+                'reading_method' => $product->reading_method,
+                'source_name' => $sourceName ?? $product->reading_method,
+                'base_price' => $basePrice,
+                'base_profit' => $baseProfit,
+                'offset_percent' => 0.0,
+                'old_price' => $oldPrice,
+                'new_price' => $computed,
+                'changed' => $oldPrice !== $computed,
+                'price_formula' => true,
+            ];
+        }
+
         $offsetPercent = self::offsetPercent($product);
         $adjustedPrice = self::adjustedTotal($basePrice, $baseProfit, $offsetPercent);
         $oldPrice = (int) ($product->price ?? 0);