feat: Phase 6.2 팝업관리 API 구현

- popups 테이블 마이그레이션 생성
- Popup 모델 (BelongsToTenant, SoftDeletes)
- PopupService CRUD 구현
- FormRequest 검증 (Store/Update)
- PopupController 6개 엔드포인트
- Swagger 문서 (PopupApi.php)
- PROJECT_DEVELOPMENT_POLICY.md 정책 준수

app/Http/Requests/V1/Popup/StorePopupRequest.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace App\Http\Requests\V1\Popup;
+
+use App\Models\Popups\Popup;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+
+class StorePopupRequest extends FormRequest
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     */
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        return [
+            'target_type' => ['sometimes', 'string', Rule::in(array_keys(Popup::TARGET_TYPES))],
+            'target_id' => ['nullable', 'integer', 'exists:departments,id'],
+            'title' => ['required', 'string', 'max:200'],
+            'content' => ['required', 'string'],
+            'status' => ['sometimes', 'string', Rule::in(array_keys(Popup::STATUSES))],
+            'started_at' => ['nullable', 'date'],
+            'ended_at' => ['nullable', 'date', 'after_or_equal:started_at'],
+            'options' => ['nullable', 'array'],
+        ];
+    }
+
+    /**
+     * Get custom messages for validator errors.
+     *
+     * @return array<string, string>
+     */
+    public function messages(): array
+    {
+        return [
+            'target_type.in' => __('validation.in', ['attribute' => '대상 유형']),
+            'target_id.exists' => __('validation.exists', ['attribute' => '대상 부서']),
+            'title.required' => __('validation.required', ['attribute' => '제목']),
+            'title.max' => __('validation.max.string', ['attribute' => '제목', 'max' => 200]),
+            'content.required' => __('validation.required', ['attribute' => '내용']),
+            'status.in' => __('validation.in', ['attribute' => '상태']),
+            'ended_at.after_or_equal' => __('validation.after_or_equal', ['attribute' => '종료일', 'date' => '시작일']),
+        ];
+    }
+}

app/Http/Requests/V1/Popup/UpdatePopupRequest.php

@@ -0,0 +1,53 @@
+<?php
+
+namespace App\Http\Requests\V1\Popup;
+
+use App\Models\Popups\Popup;
+use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Validation\Rule;
+
+class UpdatePopupRequest extends FormRequest
+{
+    /**
+     * Determine if the user is authorized to make this request.
+     */
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    /**
+     * Get the validation rules that apply to the request.
+     *
+     * @return array<string, \Illuminate\Contracts\Validation\ValidationRule|array<mixed>|string>
+     */
+    public function rules(): array
+    {
+        return [
+            'target_type' => ['sometimes', 'string', Rule::in(array_keys(Popup::TARGET_TYPES))],
+            'target_id' => ['nullable', 'integer', 'exists:departments,id'],
+            'title' => ['sometimes', 'string', 'max:200'],
+            'content' => ['sometimes', 'string'],
+            'status' => ['sometimes', 'string', Rule::in(array_keys(Popup::STATUSES))],
+            'started_at' => ['nullable', 'date'],
+            'ended_at' => ['nullable', 'date', 'after_or_equal:started_at'],
+            'options' => ['nullable', 'array'],
+        ];
+    }
+
+    /**
+     * Get custom messages for validator errors.
+     *
+     * @return array<string, string>
+     */
+    public function messages(): array
+    {
+        return [
+            'target_type.in' => __('validation.in', ['attribute' => '대상 유형']),
+            'target_id.exists' => __('validation.exists', ['attribute' => '대상 부서']),
+            'title.max' => __('validation.max.string', ['attribute' => '제목', 'max' => 200]),
+            'status.in' => __('validation.in', ['attribute' => '상태']),
+            'ended_at.after_or_equal' => __('validation.after_or_equal', ['attribute' => '종료일', 'date' => '시작일']),
+        ];
+    }
+}