feat: add custom Dockerfile

Dockerfile

@@ -0,0 +1,19 @@
+FROM node:22-alpine
+
+WORKDIR /app
+
+# Copy package files
+COPY package*.json ./
+
+# Install dependencies (no cache mount issues)
+RUN npm install --legacy-peer-deps
+
+# Copy source
+COPY . .
+
+# Build
+RUN npm run build
+
+# Start
+EXPOSE 3000
+CMD ["npm", "start"]