add dockerfile for client

proxy-client.dockerfile

@@ -0,0 +1,23 @@
+# syntax=docker/dockerfile:1
+FROM golang:1.23 AS builder
+ARG VERSION
+WORKDIR /build
+ADD go.mod /build/
+RUN --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 GOOS=linux \
+       go mod download
+ADD . /build/
+RUN --mount=type=cache,target=/root/.cache/go-build CGO_ENABLED=0 GOOS=linux \
+    go build \
+        -trimpath \
+        -ldflags "-s -X github.com/flashbots/cvm-reverse-proxy/common.Version=${VERSION}" \
+        -v \
+        -o proxy-client \
+    cmd/proxy-client/main.go
+
+FROM alpine:latest
+WORKDIR /app
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+COPY --from=builder /build/proxy-client /app/proxy-client
+ENV LISTEN_ADDR=":8080"
+EXPOSE 8080
+CMD ["/app/proxy-client"]