feat: 접근성 검사 표준 선택 기능 — WCAG/KWCAG 버전별 선택 지원

3가지 검사 모드(한 페이지, 사이트 크롤링, 목록 업로드) 모두에서 접근성 표준을
선택할 수 있도록 추가. WCAG 2.0 A/AA, 2.1 AA, 2.2 AA와 KWCAG 2.1, 2.2를
지원하며, KWCAG 선택 시 axe-core 결과를 KWCAG 검사항목으로 자동 매핑.

- KWCAG 2.2 (33항목) / 2.1 (24항목) ↔ WCAG 매핑 테이블 (kwcag_mapping.py)
- AccessibilityChecker에 표준 파싱 및 KWCAG 변환 로직 추가
- 전체 API 파이프라인에 accessibility_standard 파라미터 전파
- 프론트엔드 3개 폼에 공용 표준 선택 드롭다운 추가

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

backend/app/services/batch_inspection_service.py

@@ -46,6 +46,7 @@ class BatchInspectionService:
         name: str,
         urls: list[str],
         concurrency: int = 4,
+        accessibility_standard: str = "wcag_2.1_aa",
     ) -> str:
         """
         Start a batch inspection.
@@ -92,6 +93,7 @@ class BatchInspectionService:
             "completed_at": None,
             "config": {
                 "concurrency": concurrency,
+                "accessibility_standard": accessibility_standard,
             },
             "source_urls": urls,
             "discovered_pages": discovered_pages,
@@ -100,13 +102,13 @@ class BatchInspectionService:
         await self.db.batch_inspections.insert_one(doc)
 
         logger.info(
-            "Batch inspection started: id=%s, name=%s, total_urls=%d, concurrency=%d",
-            batch_inspection_id, name, len(urls), concurrency,
+            "Batch inspection started: id=%s, name=%s, total_urls=%d, concurrency=%d, standard=%s",
+            batch_inspection_id, name, len(urls), concurrency, accessibility_standard,
         )
 
         # Launch background task
         asyncio.create_task(
-            self._inspect_all(batch_inspection_id, urls, concurrency)
+            self._inspect_all(batch_inspection_id, urls, concurrency, accessibility_standard)
         )
 
         return batch_inspection_id
@@ -205,6 +207,7 @@ class BatchInspectionService:
         batch_inspection_id: str,
         urls: list[str],
         concurrency: int = 4,
+        accessibility_standard: str = "wcag_2.1_aa",
     ) -> None:
         """
         Background task that inspects all URLs in parallel.
@@ -225,6 +228,7 @@ class BatchInspectionService:
                     page_url=url,
                     page_index=idx,
                     total_pages=len(urls),
+                    accessibility_standard=accessibility_standard,
                 )
                 for idx, url in enumerate(urls)
             ]
@@ -287,6 +291,7 @@ class BatchInspectionService:
         page_url: str,
         page_index: int,
         total_pages: int,
+        accessibility_standard: str = "wcag_2.1_aa",
     ) -> None:
         """Inspect a single page with semaphore-controlled concurrency."""
         async with semaphore:
@@ -295,6 +300,7 @@ class BatchInspectionService:
                 page_url=page_url,
                 page_index=page_index,
                 total_pages=total_pages,
+                accessibility_standard=accessibility_standard,
             )
 
     async def _inspect_single_page(
@@ -303,6 +309,7 @@ class BatchInspectionService:
         page_url: str,
         page_index: int,
         total_pages: int,
+        accessibility_standard: str = "wcag_2.1_aa",
     ) -> None:
         """Run inspection for a single page in the batch."""
         inspection_id = str(uuid.uuid4())
@@ -347,6 +354,7 @@ class BatchInspectionService:
                 url=page_url,
                 inspection_id=inspection_id,
                 progress_callback=page_progress_callback,
+                accessibility_standard=accessibility_standard,
             )
 
             overall_score = result.get("overall_score", 0)