Add Docker support to simplify deployment

Dockerfile

@@ -0,0 +1,32 @@
+FROM node:24-bookworm
+
+WORKDIR /app
+
+# System dependencies used by native modules and image/audio commands.
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    ffmpeg \
+    git \
+    graphicsmagick \
+    imagemagick \
+    libgif-dev \
+    libjpeg62-turbo-dev \
+    liblqr-1-0 \
+    libpango1.0-dev \
+    librsvg2-dev \
+    make \
+    g++ \
+    python3 \
+ && rm -rf /var/lib/apt/lists/*
+
+COPY package*.json ./
+RUN npm install --omit=dev && npm cache clean --force
+
+COPY . .
+
+# Refresh parse-domain data when available.
+RUN npx --yes parse-domain-update || true
+
+ENV NODE_ENV=production
+
+CMD ["node", "Xiao.js"]