fix: Add missing Dockerfile and lint script for CI/CD workflows

- Add Dockerfile for multi-stage Node.js build with production optimizations
- Add lint script to package.json that runs TypeScript type checking
- Enable health check endpoint in Docker container
- Configure proper user permissions and security practices

Fixes docker-build workflow failures and enables complete CI/CD pipeline.

Dockerfile

@@ -0,0 +1,55 @@
+# Multi-stage build for Node.js frontend application
+FROM node:20-alpine AS builder
+
+# Install yarn
+RUN apk add --no-cache yarn
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package.json yarn.lock ./
+
+# Install dependencies
+RUN yarn install --frozen-lockfile
+
+# Copy source code
+COPY . .
+
+# Build the application
+RUN yarn build
+
+# Production stage
+FROM node:20-alpine AS production
+
+# Install yarn for production
+RUN apk add --no-cache yarn
+
+# Create app user
+RUN addgroup -g 1001 -S nodejs
+RUN adduser -S nextjs -u 1001
+
+# Set working directory
+WORKDIR /app
+
+# Copy package files
+COPY package.json yarn.lock ./
+
+# Install only production dependencies
+RUN yarn install --frozen-lockfile --production && yarn cache clean
+
+# Copy built application from builder stage
+COPY --from=builder --chown=nextjs:nodejs /app/dist ./dist
+
+# Switch to non-root user
+USER nextjs
+
+# Expose the application port
+EXPOSE 3000
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=3s --start-period=5s --retries=3 \
+  CMD node -e "require('http').get('http://localhost:3000/health', (res) => { process.exit(res.statusCode === 200 ? 0 : 1) }).on('error', () => process.exit(1))"
+
+# Command to run the application
+CMD ["yarn", "start"]

package.json

@@ -7,7 +7,8 @@
 		"dev": "NODE_ENV=development tsx server/index.ts",
 		"build": "vite build && esbuild server/index.ts --platform=node --packages=external --bundle --format=esm --outdir=dist",
 		"start": "NODE_ENV=production node dist/index.js",
-		"check": "tsc"
+		"check": "tsc",
+		"lint": "yarn check"
 	},
 	"dependencies": {
 		"@anthropic-ai/sdk": "^0.37.0",