feat: add docker deployment support

Dockerfile

@@ -0,0 +1,34 @@
+# syntax=docker/dockerfile:1
+
+FROM golang:1.24.4-alpine AS build
+
+WORKDIR /src
+
+COPY go.mod go.sum ./
+RUN --mount=type=cache,id=mc-gateway-go-mod,target=/go/pkg/mod,sharing=locked \
+    go mod download
+
+COPY . .
+RUN --mount=type=cache,id=mc-gateway-go-mod,target=/go/pkg/mod,sharing=locked \
+    --mount=type=cache,id=mc-gateway-go-build,target=/root/.cache/go-build,sharing=locked \
+    CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /out/mc-gateway ./cmd/gateway
+
+FROM alpine:3.22
+
+RUN apk add --no-cache su-exec \
+    && addgroup -S mc-gateway \
+    && adduser -S -G mc-gateway mc-gateway
+
+WORKDIR /data
+RUN chown mc-gateway:mc-gateway /data
+
+COPY --from=build /out/mc-gateway /usr/local/bin/mc-gateway
+COPY docker-entrypoint.sh /usr/local/bin/docker-entrypoint.sh
+RUN chmod +x /usr/local/bin/docker-entrypoint.sh
+
+ENV MC_GATEWAY_DB=/data/mc-gateway.sqlite3
+
+EXPOSE 25565/tcp
+
+ENTRYPOINT ["/usr/local/bin/docker-entrypoint.sh"]
+CMD ["/usr/local/bin/mc-gateway"]