Fix PDF font loading for project overview reports

docker/backend/Dockerfile

@@ -2,6 +2,10 @@ FROM eclipse-temurin:21-jre-jammy
 
 WORKDIR /app
 
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends fontconfig fonts-wqy-microhei \
+    && rm -rf /var/lib/apt/lists/*
+
 COPY backend/ruoyi-admin.jar /app/ruoyi-admin.jar
 
 RUN mkdir -p /app/data/ruoyi /app/logs