feat(labor): 노임관리 API 구현

- Labor 모델 (BelongsToTenant, SoftDeletes)
- LaborController 7개 엔드포인트
- LaborService 비즈니스 로직
- FormRequest 4개 (Index/Store/Update/BulkDelete)
- 마이그레이션 및 라우트 등록

API: GET/POST /labor, GET/PUT/DELETE /labor/{id}, DELETE /labor/bulk, GET /labor/stats

Co-Authored-By: Claude <noreply@anthropic.com>

app/Http/Requests/Labor/LaborIndexRequest.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace App\Http\Requests\Labor;
+
+use Illuminate\Foundation\Http\FormRequest;
+
+class LaborIndexRequest extends FormRequest
+{
+    public function authorize(): bool
+    {
+        return true;
+    }
+
+    public function rules(): array
+    {
+        return [
+            'search' => ['nullable', 'string', 'max:100'],
+            'category' => ['nullable', 'string', 'in:가로,세로할증'],
+            'status' => ['nullable', 'string', 'in:사용,중지'],
+            'start_date' => ['nullable', 'date'],
+            'end_date' => ['nullable', 'date', 'after_or_equal:start_date'],
+            'page' => ['nullable', 'integer', 'min:1'],
+            'per_page' => ['nullable', 'integer', 'min:1', 'max:100'],
+            'sort_by' => ['nullable', 'string', 'in:created_at,labor_number,category,min_m,max_m,labor_price'],
+            'sort_dir' => ['nullable', 'string', 'in:asc,desc'],
+        ];
+    }
+
+    public function messages(): array
+    {
+        return [
+            'category.in' => __('validation.in', ['attribute' => '구분']),
+            'status.in' => __('validation.in', ['attribute' => '상태']),
+            'end_date.after_or_equal' => __('validation.after_or_equal', ['attribute' => '종료일', 'date' => '시작일']),
+        ];
+    }
+}