feat: [attendance] attendance_requests 테이블 마이그레이션 추가

- 근태 승인 워크플로우용 신청 테이블
- tenant_id, user_id, request_type, start_date, end_date, status 등

database/migrations/2026_02_26_100000_create_attendance_requests_table.php

@@ -0,0 +1,39 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('attendance_requests', function (Blueprint $table) {
+            $table->id();
+            $table->unsignedBigInteger('tenant_id');
+            $table->unsignedBigInteger('user_id')->comment('신청자');
+            $table->enum('request_type', ['vacation', 'businessTrip', 'remote', 'fieldWork'])->comment('신청 유형');
+            $table->date('start_date');
+            $table->date('end_date');
+            $table->text('reason')->nullable()->comment('사유');
+            $table->enum('status', ['pending', 'approved', 'rejected'])->default('pending');
+            $table->unsignedBigInteger('approved_by')->nullable()->comment('승인자');
+            $table->timestamp('approved_at')->nullable();
+            $table->text('reject_reason')->nullable()->comment('반려 사유');
+            $table->json('json_details')->nullable()->comment('반차 구분 등 추가 정보');
+            $table->timestamps();
+            $table->softDeletes();
+
+            $table->foreign('tenant_id')->references('id')->on('tenants')->cascadeOnDelete();
+            $table->foreign('user_id')->references('id')->on('users')->cascadeOnDelete();
+
+            $table->index(['tenant_id', 'status']);
+            $table->index(['tenant_id', 'user_id']);
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('attendance_requests');
+    }
+};