fix: add build deps for lxml

Dockerfile

@@ -2,6 +2,11 @@ FROM python:3.12-slim
 
 WORKDIR /app
 
+# lxml 등 C 의존성 빌드에 필요
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    gcc g++ libxml2-dev libxslt1-dev \
+    && rm -rf /var/lib/apt/lists/*
+
 # uv 설치
 RUN pip install --no-cache-dir uv