perf(docker): 依赖下载全部换国内源(内网构建提速)

go mod download 走默认 proxy.golang.org 内网极慢。四个 Dockerfile 统一换国内镜像:
- Go: GOPROXY=https://goproxy.cn,direct(三个 Go 服务)
- alpine: apk 源换 mirrors.aliyun.com(ca-certificates/tzdata)
- pip: mcp-py 换清华 pypi 源
- npm: gateway admin 已在用 npmmirror(此前已有)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

sundynix-mcp-go/Dockerfile

@@ -5,7 +5,7 @@ WORKDIR /src
 COPY sundynix-shared/go.mod sundynix-shared/go.sum ./sundynix-shared/
 COPY sundynix-mcp-go/go.mod sundynix-mcp-go/go.sum ./sundynix-mcp-go/
 WORKDIR /src/sundynix-mcp-go
-ENV GOWORK=off GOFLAGS=-mod=mod
+ENV GOWORK=off GOFLAGS=-mod=mod GOPROXY=https://goproxy.cn,direct
 RUN go mod download
 WORKDIR /src
 COPY sundynix-shared/ ./sundynix-shared/
@@ -15,7 +15,8 @@ RUN CGO_ENABLED=0 go build -trimpath -ldflags="-s -w" -o /out/mcp-go ./cmd/serve
 
 # alpine 运行（内网 runner 连不上 gcr.io；二进制 CGO_ENABLED=0 全静态，ca-certs 供 TLS）。
 FROM alpine:3.20
-RUN apk add --no-cache ca-certificates tzdata && adduser -D -u 10001 app
+RUN sed -i 's#dl-cdn.alpinelinux.org#mirrors.aliyun.com#g' /etc/apk/repositories \
+    && apk add --no-cache ca-certificates tzdata && adduser -D -u 10001 app
 USER app
 COPY --from=build /out/mcp-go /mcp-go
 ENTRYPOINT ["/mcp-go"]