added docker setup

docker/Dockerfile

@@ -0,0 +1,97 @@
+# ===================================
+# Stage 1: Build Frontend
+# ===================================
+FROM node:20-alpine AS frontend-builder
+
+WORKDIR /app/frontend
+
+# Copy package files
+COPY frontend/package*.json ./
+
+# Install dependencies
+RUN npm ci
+
+# Copy frontend source
+COPY frontend/ ./
+
+# Build frontend
+RUN npm run build
+
+# ===================================
+# Stage 2: Build Backend
+# ===================================
+FROM node:20-alpine AS backend-builder
+
+WORKDIR /app/backend
+
+# Install OpenSSL for Prisma
+RUN apk add --no-cache openssl
+
+# Copy package files
+COPY backend/package*.json ./
+
+# Install dependencies (including dev for build)
+RUN npm ci
+
+# Copy backend source
+COPY backend/ ./
+
+# Generate Prisma client
+RUN npx prisma generate
+
+# Build TypeScript
+RUN npm run build
+
+# ===================================
+# Stage 3: Production Runtime
+# ===================================
+FROM node:20-alpine AS production
+
+WORKDIR /app
+
+# Install OpenSSL for Prisma runtime and netcat for DB health check
+RUN apk add --no-cache openssl netcat-openbsd
+
+# Create non-root user
+RUN addgroup -g 1001 -S nodejs && \
+    adduser -S opencrm -u 1001 -G nodejs
+
+# Copy backend package files
+COPY backend/package*.json ./
+
+# Install production dependencies + tsx for seed script
+RUN npm ci --omit=dev && npm install tsx
+
+# Copy Prisma schema and generate client
+COPY backend/prisma ./prisma
+RUN npx prisma generate
+
+# Copy built backend
+COPY --from=backend-builder /app/backend/dist ./dist
+
+# Copy built frontend to public directory
+COPY --from=frontend-builder /app/frontend/dist ./public
+
+# Copy seed file for factory reset
+COPY backend/prisma/seed.ts ./prisma/
+
+# Copy entrypoint script
+COPY docker/entrypoint.sh ./entrypoint.sh
+
+# Create directories for uploads and backups
+RUN mkdir -p uploads backups && \
+    chmod +x entrypoint.sh && \
+    chown -R opencrm:nodejs /app
+
+# Switch to non-root user
+USER opencrm
+
+# Expose port
+EXPOSE 3001
+
+# Health check
+HEALTHCHECK --interval=30s --timeout=10s --start-period=30s --retries=3 \
+    CMD wget --no-verbose --tries=1 --spider http://localhost:3001/api/health || exit 1
+
+# Start the application with entrypoint
+ENTRYPOINT ["./entrypoint.sh"]