feat: Add Dockerfile for Railway deployment

- Create optimized Dockerfile for n8n enterprise unlocked
- Use Node.js 20 Alpine for smaller image size
- Install pnpm and build all packages
- Configure production environment variables
- Expose port 5678 for Railway deployment

Dockerfile

@@ -0,0 +1,42 @@
+# Dockerfile for n8n Enterprise Unlocked
+FROM node:20-alpine
+
+# Install pnpm
+RUN npm install -g pnpm@latest
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package.json pnpm-workspace.yaml pnpm-lock.yaml ./
+COPY packages/cli/package.json ./packages/cli/
+
+# Copy all package.json files for proper dependency resolution
+COPY packages/@n8n/*/package.json ./packages/@n8n/*/
+COPY packages/frontend/*/package.json ./packages/frontend/*/
+COPY packages/core/package.json ./packages/core/
+COPY packages/workflow/package.json ./packages/workflow/
+COPY packages/nodes-base/package.json ./packages/nodes-base/
+COPY packages/node-dev/package.json ./packages/node-dev/
+COPY packages/testing/package.json ./packages/testing/
+COPY packages/extensions/*/package.json ./packages/extensions/*/
+
+# Install dependencies
+RUN pnpm install --frozen-lockfile
+
+# Copy source code
+COPY . .
+
+# Build the application
+RUN pnpm build
+
+# Expose port
+EXPOSE 5678
+
+# Set environment variables
+ENV N8N_HOST=0.0.0.0
+ENV N8N_PORT=5678
+ENV NODE_ENV=production
+
+# Start n8n
+CMD ["pnpm", "--filter=n8n", "start"]