feat(API): 작업일지 생성/조회 API 추가

- WorkOrderService: getWorkLogTemplate, getWorkLog, createWorkLog 메서드 추가
- WorkOrderController: 작업일지 3개 엔드포인트 추가
- 라우트: GET work-log-template, GET/POST work-log
- WorkOrder 모델: documents() MorphMany 관계 추가
- i18n: work_log_saved, no_work_log_template 메시지 추가

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/Models/Production/WorkOrder.php

@@ -2,6 +2,7 @@
 
 namespace App\Models\Production;
 
+use App\Models\Documents\Document;
 use App\Models\Members\User;
 use App\Models\Orders\Order;
 use App\Models\Process;
@@ -14,6 +15,7 @@
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\Relations\HasOne;
+use Illuminate\Database\Eloquent\Relations\MorphMany;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
 /**
@@ -203,6 +205,14 @@ public function stepProgress(): HasMany
         return $this->hasMany(WorkOrderStepProgress::class);
     }
 
+    /**
+     * 문서 (중간검사, 작업일지 등)
+     */
+    public function documents(): MorphMany
+    {
+        return $this->morphMany(Document::class, 'linkable');
+    }
+
     /**
      * 출하 목록
      */