feat: 대시보드 API 및 FCM 푸시 알림 API 구현

Dashboard API:
- DashboardController, DashboardService 추가
- /dashboard/summary, /charts, /approvals 엔드포인트

Push Notification API:
- FCM 토큰 관리 (등록/해제/목록)
- 알림 설정 관리 (유형별 on/off, 알림음 설정)
- 알림 유형: deposit, withdrawal, order, approval, attendance, notice, system
- 알림음: default, deposit, withdrawal, order, approval, urgent
- PushDeviceToken, PushNotificationSetting 모델
- Swagger 문서 추가

app/Http/Requests/V1/Dashboard/DashboardApprovalsRequest.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Http\Requests\V1\Dashboard;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class DashboardApprovalsRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'limit' => ['nullable', 'integer', 'min:1', 'max:50'],
+        ];
+    }
+
+    public function messages(): array
+    {
+        return [
+            'limit.min' => __('error.validation.min', ['min' => 1]),
+            'limit.max' => __('error.validation.max', ['max' => 50]),
+        ];
+    }
+}

app/Http/Requests/V1/Dashboard/DashboardChartsRequest.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace App\Http\Requests\V1\Dashboard;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class DashboardChartsRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'period' => ['nullable', 'string', 'in:week,month,quarter'],
+        ];
+    }
+
+    public function messages(): array
+    {
+        return [
+            'period.in' => __('error.dashboard.invalid_period'),
+        ];
+    }
+}