refactor: 重構模組通訊與調整儀表板功能

- 依循跨模組通訊規範，將 Sales 與 Production 模組中對 Inventory 的直接模型關聯改為透過 InventoryServiceInterface 取得
- 於 InventoryService 實作獲取最高庫存價值、即將過期商品等方法，供儀表板使用
- 確保所有跨模組調用皆採用手動水和（Manual Hydration）方式組合資料
- 移除本地已歸檔的 .agent 規範檔案

app/Modules/Sales/Imports/SalesImportSheet.php

@@ -4,7 +4,7 @@ namespace App\Modules\Sales\Imports;
 
 use App\Modules\Sales\Models\SalesImportBatch;
 use App\Modules\Sales\Models\SalesImportItem;
-use App\Modules\Inventory\Models\Product;
+use App\Modules\Inventory\Contracts\InventoryServiceInterface;
 use Illuminate\Support\Collection;
 use Maatwebsite\Excel\Concerns\ToCollection;
 use Maatwebsite\Excel\Concerns\WithStartRow;
@@ -19,7 +19,8 @@ class SalesImportSheet implements ToCollection, WithStartRow
     {
         $this->batch = $batch;
         // Pre-load all products to minimize queries (keyed by code)
-        $this->products = Product::pluck('id', 'code'); // assumes code is unique
+        $inventoryService = app(InventoryServiceInterface::class);
+        $this->products = $inventoryService->getAllProducts()->pluck('id', 'code')->toArray(); // assumes code is unique
     }
 
     public function startRow(): int