Refactor RDP proxy handling and update related tests

agents/rap-node-agent/Dockerfile.fabric-loadtest

@@ -0,0 +1,17 @@
+FROM golang:1.25-bookworm AS build
+
+WORKDIR /src
+COPY agents/rap-node-agent/go.mod ./
+COPY agents/rap-node-agent/go.sum ./
+RUN go mod download
+COPY agents/rap-node-agent/ ./
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o /out/fabric-loadtest ./cmd/fabric-loadtest
+
+FROM debian:bookworm-slim
+
+RUN apt-get update \
+    && apt-get install -y --no-install-recommends ca-certificates iproute2 iptables iputils-ping procps \
+    && rm -rf /var/lib/apt/lists/*
+COPY --from=build /out/fabric-loadtest /usr/local/bin/fabric-loadtest
+ENTRYPOINT ["/usr/local/bin/fabric-loadtest"]
+