fix: Revert to aspnet runtime - FrontOffice is Blazor Server not WASM

- Project uses Microsoft.NET.Sdk.Web (Blazor Server)
- Not Microsoft.NET.Sdk.BlazorWebAssembly
- Needs aspnet runtime to run the .dll, not nginx for static files
- Changed back from nginx:alpine to aspnet:9.0

src/FrontOffice.Main/Dockerfile

@@ -15,24 +15,12 @@ COPY . .
 WORKDIR "/src/FrontOffice.Main"
 RUN dotnet publish "FrontOffice.Main.csproj" -c Release -o /app/publish
 
-# Runtime stage - nginx for Blazor WebAssembly
-FROM nginx:alpine AS final
-WORKDIR /usr/share/nginx/html
-
-# Remove default nginx files
-RUN rm -rf /usr/share/nginx/html/*
-
-# Copy published wwwroot (Blazor WASM output)
-COPY --from=build /app/publish/wwwroot .
-
-# Configure nginx for SPA routing
-RUN echo 'server { \
-    listen 80; \
-    server_name _; \
-    location / { \
-        root /usr/share/nginx/html; \
-        try_files $uri $uri/ /index.html; \
-    } \
-}' > /etc/nginx/conf.d/default.conf
+# Runtime stage - aspnet for Blazor Server
+FROM mcr.microsoft.com/dotnet/aspnet:9.0 AS runtime
+WORKDIR /app
+COPY --from=build /app/publish .
 
+ENV ASPNETCORE_URLS=http://+:80
 EXPOSE 80
+
+ENTRYPOINT ["dotnet", "FrontOffice.Main.dll"]