fix: 修复前端访问错误

frontend/.dockerignore

@@ -0,0 +1,7 @@
+node_modules
+dist
+.git
+.gitignore
+*.md
+.DS_Store
+npm-debug.log*

frontend/Dockerfile

@@ -9,7 +9,9 @@ COPY package.json /app/package.json
 RUN npm config set registry https://registry.npmmirror.com && npm install
 
 COPY . /app
-RUN npm run build
+RUN npm run build \
+  && test -f /app/dist/index.html \
+  && ls -la /app/dist
 
 FROM nginx:1.27-alpine
 RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories