chore: replace manual SQL migrations with node-pg-migrate

backend/Dockerfile

@@ -0,0 +1,25 @@
+FROM node:20-bookworm-slim AS frontend-build
+WORKDIR /app/frontend
+COPY frontend/package.json ./
+RUN npm install
+COPY frontend/ ./
+RUN npm run build
+
+FROM node:20-bookworm-slim AS backend-build
+WORKDIR /app/backend
+COPY backend/package.json ./
+RUN npm install
+COPY backend/ ./
+RUN npm run build
+
+FROM node:20-bookworm-slim
+WORKDIR /app
+COPY --from=backend-build /app/backend/package.json ./
+RUN npm install --omit=dev
+COPY --from=backend-build /app/backend/dist ./dist
+COPY --from=backend-build /app/backend/migrate.js ./migrate.js
+COPY --from=backend-build /app/backend/migrations ./migrations
+COPY --from=frontend-build /app/frontend/dist ./public
+ENV NODE_ENV=production
+EXPOSE 3000
+CMD ["node", "dist/server.js"]