feat: 新增採購統計分析功能並優化 API 文件顯示樣式

- 在 RoleController 中新增 procurement_analysis 權限群組名稱
- 在 Procurement 模組中新增採購統計分析路由
- 在 PermissionSeeder 中新增 procurement_analysis.view 權限並分配給角色
- 在側邊欄「報表與分析」分組中新增「採購統計分析」項目
- 優化 API 文件視圖中的表格外觀樣式

app/Modules/Procurement/Controllers/ProcurementAnalysisController.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace App\Modules\Procurement\Controllers;
+
+use App\Http\Controllers\Controller;
+use App\Modules\Procurement\Services\ProcurementAnalysisService;
+use App\Modules\Procurement\Models\Vendor;
+use App\Modules\Inventory\Contracts\InventoryServiceInterface;
+use Illuminate\Http\Request;
+use Inertia\Inertia;
+
+class ProcurementAnalysisController extends Controller
+{
+    public function __construct(
+        protected ProcurementAnalysisService $analysisService,
+        protected InventoryServiceInterface $inventoryService,
+    ) {}
+
+    public function index(Request $request)
+    {
+        $filters = $request->only([
+            'date_from', 'date_to', 'vendor_id', 'warehouse_id',
+        ]);
+
+        // 取得各面向數據
+        $kpis = $this->analysisService->getKPIs($filters);
+        $deliveryAnalysis = $this->analysisService->getDeliveryAnalysis($filters);
+        $quantityAnalysis = $this->analysisService->getQuantityAnalysis($filters);
+        $priceTrendAnalysis = $this->analysisService->getPriceTrendAnalysis($filters);
+
+        // 取得篩選器選項（跨模組透過 Service 取得倉庫）
+        $warehouses = $this->inventoryService->getAllWarehouses();
+        $vendors = Vendor::select('id', 'name', 'code')->orderBy('name')->get();
+
+        return Inertia::render('Procurement/Analysis/Index', [
+            'kpis' => $kpis,
+            'deliveryAnalysis' => $deliveryAnalysis,
+            'quantityAnalysis' => $quantityAnalysis,
+            'priceTrendAnalysis' => $priceTrendAnalysis,
+            'vendors' => $vendors,
+            'warehouses' => $warehouses,
+            'filters' => $filters,
+        ]);
+    }
+}