Add waiting system application files

- Add main application files (main.py, models.py, schemas.py, etc.)
- Add routers for all features (waiting, attendance, members, etc.)
- Add HTML templates for admin and user interfaces
- Add migration scripts and utility files
- Add Docker configuration
- Add documentation files
- Add .gitignore to exclude database and cache files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

routers/sse.py

@@ -0,0 +1,38 @@
+from fastapi import APIRouter
+from fastapi.responses import StreamingResponse
+from sse_manager import sse_manager, event_generator
+
+router = APIRouter()
+
+
+@router.get("/stream")
+async def sse_stream(store_id: str):
+    """
+    SSE 스트림 엔드포인트
+    - 매장별로 실시간 이벤트를 수신
+    - 클라이언트는 EventSource로 연결
+    - Query parameter: store_id
+    """
+    # 새로운 연결 등록
+    print(f"[SSE] Connection Request: store_id={store_id}")
+    queue = await sse_manager.connect(store_id)
+
+    async def cleanup():
+        """연결 종료 시 정리"""
+        sse_manager.disconnect(store_id, queue)
+
+    # SSE 응답 생성
+    response = StreamingResponse(
+        event_generator(queue),
+        media_type="text/event-stream",
+        headers={
+            "Cache-Control": "no-cache",
+            "Connection": "keep-alive",
+            "X-Accel-Buffering": "no",  # Nginx 버퍼링 비활성화
+        }
+    )
+
+    # 연결 종료 시 cleanup 호출하도록 설정
+    response.background = cleanup
+
+    return response