新增: df-relay Dockerfile + .dockerignore(云端部署基建)

docker build -f crates/df-relay/Dockerfile -t df-relay .(context=repo根,multi-stage rust:slim 编译→debian 运行)。容器内 :8080(DF_RELAY_ADDR),宿主映射 :9180 避开测试机 8080 占用。

crates/df-relay/Dockerfile

@@ -0,0 +1,21 @@
+# df-relay 跨端中继(Phase3 云端部署,u-work.1216.top)
+# multi-stage:rust:slim 编译 df-relay → debian:slim 运行(static-ish binary)
+#
+# 构建(context = repo 根,workspace):
+#   docker build -f crates/df-relay/Dockerfile -t df-relay .
+# 运行(容器内 :8080,映射宿主 :9180,避开测试机 8080 占用):
+#   docker run -d --name df-relay --restart unless-stopped -p 9180:8080 df-relay
+
+FROM rust:1.85-slim AS builder
+WORKDIR /build
+COPY . .
+RUN cargo build --release -p df-relay
+
+FROM debian:bookworm-slim
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+COPY --from=builder /build/target/release/df-relay /usr/local/bin/df-relay
+ENV DF_RELAY_ADDR=0.0.0.0:8080
+EXPOSE 8080
+CMD ["df-relay"]