feat: wiring the worker in the main loop

Dockerfile

@@ -8,7 +8,14 @@ RUN go mod download
 COPY . .
 RUN CGO_ENABLED=0 go build -v -ldflags="-s -w" -o /usr/bin/app ./...
 
+# Empty cache dir; ownership is set during COPY into the final stage so the
+# distroless `nonroot` user (uid 65532) can write to it without an external
+# volume mount.
+RUN mkdir -p /cache
+
 FROM gcr.io/distroless/static:nonroot
 EXPOSE 8080
 COPY --from=build /usr/bin/app /app
+COPY --from=build --chown=65532:65532 /cache /var/cache/pz8-relay
+VOLUME /var/cache/pz8-relay
 ENTRYPOINT ["/app"]