feat: 웹사이트 표준화 검사 도구 구현

- 4개 검사 엔진: HTML/CSS, 접근성(WCAG), SEO, 성능/보안 (총 50개 항목)
- FastAPI 백엔드 (9개 API, SSE 실시간 진행, PDF/JSON 리포트)
- Next.js 15 프론트엔드 (6개 페이지, 29개 컴포넌트, 반원 게이지 차트)
- Docker Compose 배포 (Backend:8011, Frontend:3011, MongoDB:27022, Redis:6392)
- 전체 테스트 32/32 PASS

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

backend/app/models/database.py

@@ -0,0 +1,33 @@
+"""
+MongoDB document models and helper functions.
+"""
+
+from datetime import datetime, timezone
+from typing import Optional
+
+
+def create_inspection_document(
+    inspection_id: str,
+    url: str,
+    status: str,
+    overall_score: int,
+    grade: str,
+    categories: dict,
+    summary: dict,
+    created_at: datetime,
+    completed_at: Optional[datetime] = None,
+    duration_seconds: Optional[float] = None,
+) -> dict:
+    """Create a MongoDB document for the inspections collection."""
+    return {
+        "inspection_id": inspection_id,
+        "url": url,
+        "status": status,
+        "created_at": created_at,
+        "completed_at": completed_at,
+        "duration_seconds": duration_seconds,
+        "overall_score": overall_score,
+        "grade": grade,
+        "categories": categories,
+        "summary": summary,
+    }