chore: slim the worker image and streamline the Docker builds

Dockerfile

@@ -2,19 +2,15 @@ FROM --platform=$BUILDPLATFORM golang:1.27-alpine AS build
 ARG TARGETOS TARGETARCH
 ARG VERSION=dev
 WORKDIR /src
-COPY go.mod go.sum ./
-COPY cmd ./cmd
-COPY db ./db
-COPY internal ./internal
-COPY protocol ./protocol
+COPY --parents go.mod go.sum cmd db internal protocol ./
 RUN CGO_ENABLED=0 GOOS=$TARGETOS GOARCH=$TARGETARCH go build -trimpath -tags grpcnotrace \
     -ldflags "-s -w -X github.com/dihemoe/alisten/internal/bootstrap.version=$VERSION" \
-    -o /out/alisten ./cmd/alisten
+    -o /out/usr/local/bin/alisten ./cmd/alisten \
+    && install -Dm644 /etc/ssl/certs/ca-certificates.crt /out/etc/ssl/certs/ca-certificates.crt
+COPY LICENSE /out/usr/share/doc/alisten/
 
 FROM gcr.io/distroless/static-debian13:nonroot AS alisten
-COPY LICENSE /usr/share/doc/alisten/
-COPY --from=build /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
-COPY --from=build /out/alisten /usr/local/bin/alisten
+COPY --from=build /out /
 USER 65532:65532
 EXPOSE 8080 9090
 HEALTHCHECK --start-period=30s --start-interval=1s --interval=10s --timeout=3s --retries=3 \