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/Inventory/Services/InventoryService.php

@@ -16,6 +16,26 @@ class InventoryService implements InventoryServiceInterface
         return Warehouse::all();
     }
 
+    public function getTopInventoryValue(int $limit = 5): \Illuminate\Support\Collection
+    {
+        return Inventory::select('product_id', \Illuminate\Support\Facades\DB::raw('SUM(quantity * unit_cost) as total_value'))
+            ->where('quantity', '>', 0)
+            ->groupBy('product_id')
+            ->orderByDesc('total_value')
+            ->limit($limit)
+            ->get();
+    }
+
+    public function getExpiringSoon(int $limit = 5): \Illuminate\Support\Collection
+    {
+        return Inventory::where('quantity', '>', 0)
+            ->whereNotNull('expiry_date')
+            ->where('expiry_date', '>=', now()) // 只顯示未過期但即將過期的
+            ->orderBy('expiry_date', 'asc')
+            ->limit($limit)
+            ->get();
+    }
+
     public function getAllProducts()
     {
         return Product::with(['baseUnit', 'largeUnit'])->get();
@@ -41,6 +61,11 @@ class InventoryService implements InventoryServiceInterface
         return Product::whereIn('id', $ids)->with(['baseUnit', 'largeUnit'])->get();
     }
 
+    public function getWarehousesByCodes(array $codes)
+    {
+        return Warehouse::whereIn('code', $codes)->get();
+    }
+
     public function getProductsByName(string $name)
     {
         return Product::where('name', 'like', "%{$name}%")->with(['baseUnit', 'largeUnit'])->get();