build: 优化Dockerfile以使用多阶段构建

重构用户服务和推荐服务的Dockerfile，采用多阶段构建方式
- 添加构建阶段以减少最终镜像大小
- 分离SDK和运行时镜像以提高安全性
- 使用发布输出而非源代码作为运行时输入

services/recommend-service/Dockerfile

@@ -1,5 +1,16 @@
+FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
+WORKDIR /src
+COPY ["AriStockAI.Recommend.csproj", "./"]
+RUN dotnet restore "./AriStockAI.Recommend.csproj"
+COPY . .
+WORKDIR "/src/"
+RUN dotnet build "AriStockAI.Recommend.csproj" -c Release -o /app/build
+
+FROM build AS publish
+RUN dotnet publish "AriStockAI.Recommend.csproj" -c Release -o /app/publish
+
 FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
 WORKDIR /app
-COPY . .
+COPY --from=publish /app/publish .
 EXPOSE 8003
 ENTRYPOINT ["dotnet", "AriStockAI.Recommend.dll"]

services/user-service/Dockerfile

@@ -1,5 +1,16 @@
+FROM mcr.microsoft.com/dotnet/sdk:6.0 AS build
+WORKDIR /src
+COPY ["AriStockAI.User.csproj", "./"]
+RUN dotnet restore "./AriStockAI.User.csproj"
+COPY . .
+WORKDIR "/src/"
+RUN dotnet build "AriStockAI.User.csproj" -c Release -o /app/build
+
+FROM build AS publish
+RUN dotnet publish "AriStockAI.User.csproj" -c Release -o /app/publish
+
 FROM mcr.microsoft.com/dotnet/aspnet:6.0 AS base
 WORKDIR /app
-COPY . .
+COPY --from=publish /app/publish .
 EXPOSE 8004
 ENTRYPOINT ["dotnet", "AriStockAI.User.dll"]