feat(deploy): dev/prod Dockerfiles in service dirs (backend/,web/), templates live beside rendered outputs, entrypoint copies /etc/booklib conf before resolver injection

backend/Dockerfile.prod

@@ -0,0 +1,15 @@
+FROM golang:1.26-alpine AS build
+WORKDIR /src
+COPY backend/go.mod backend/go.sum ./
+RUN go mod download
+COPY backend/ ./
+RUN CGO_ENABLED=0 go build -trimpath -o /server ./cmd/server
+
+FROM alpine:3.20 AS runner
+RUN adduser -D -H app
+COPY --from=build /server /server
+# /data/books 由宿主 bind(./api/storage)覆盖;/data 下目录预建并授权,兼容 podman
+RUN mkdir -p /data && chown app:app /data
+USER app
+EXPOSE 8080
+ENTRYPOINT ["/server"]