feat: 添加docker部署

backend/Dockerfile

@@ -0,0 +1,38 @@
+#
+# Multi-stage build for backend API and worker.
+#
+# Build:
+#   docker build -f backend/Dockerfile -t feedsystem-backend:api --target api .
+#   docker build -f backend/Dockerfile -t feedsystem-backend:worker --target worker .
+#
+
+ARG GO_VERSION=1.24.5
+
+FROM golang:${GO_VERSION} AS build
+WORKDIR /src/backend
+
+COPY backend/go.mod backend/go.sum ./
+RUN go mod download
+
+COPY backend/ ./
+
+ENV CGO_ENABLED=0
+RUN go build -trimpath -ldflags="-s -w" -o /out/api ./cmd
+RUN go build -trimpath -ldflags="-s -w" -o /out/worker ./cmd/worker
+
+FROM alpine:3.21 AS base
+RUN apk add --no-cache ca-certificates tzdata && adduser -D -H -s /sbin/nologin app
+WORKDIR /app
+COPY --from=build /src/backend/configs ./configs
+RUN mkdir -p ./.run/uploads && chown -R app:app /app
+USER app
+
+FROM base AS api
+COPY --from=build /out/api /app/api
+EXPOSE 8080
+ENTRYPOINT ["/app/api"]
+
+FROM base AS worker
+COPY --from=build /out/worker /app/worker
+ENTRYPOINT ["/app/worker"]
+