revert: restore Dockerfile + cloudbuild — broker is a deployed BD service

Dockerfile

@@ -0,0 +1,25 @@
+# syntax=docker/dockerfile:1
+FROM golang:1.26.1-alpine AS builder
+
+RUN apk add --no-cache git ca-certificates
+
+ARG GITHUB_TOKEN
+RUN git config --global url."https://${GITHUB_TOKEN}@github.com/".insteadOf "https://github.com/"
+ENV GOPRIVATE=github.com/luxfi/*,github.com/hanzoai/*
+
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -ldflags="-s -w" -o brokerd ./cmd/brokerd/
+
+FROM alpine:3.21
+RUN apk add --no-cache ca-certificates
+COPY --from=builder /app/brokerd /usr/local/bin/brokerd
+EXPOSE 8090 9090
+
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:8090/healthz || exit 1
+
+ENTRYPOINT ["brokerd"]

cloudbuild.yaml

@@ -0,0 +1,14 @@
+steps:
+  - name: 'gcr.io/cloud-builders/docker'
+    args:
+      - 'build'
+      - '--build-arg=BUILDPLATFORM=linux/amd64'
+      - '--build-arg=GITHUB_TOKEN=${_GITHUB_TOKEN}'
+      - '-t'
+      - 'us-docker.pkg.dev/$PROJECT_ID/backend/broker:next'
+      - '.'
+    env:
+      - 'DOCKER_BUILDKIT=1'
+images:
+  - 'us-docker.pkg.dev/$PROJECT_ID/backend/broker:next'
+timeout: '600s'