fix(Dockerfile): copy .tunnel_key file from builder stage to ensure localtunnel functionality in production

Author: drewpayment

Dockerfile

@@ -36,6 +36,7 @@ WORKDIR /app
 COPY --from=builder /staging/package.json /staging/pnpm-lock.yaml ./
 COPY --from=builder /staging/node_modules ./node_modules
 COPY --from=builder /staging/build ./build
+COPY --from=builder /staging/.tunnel_key ./.tunnel_key
 
 EXPOSE 3000
 CMD ["node", "-r", "dotenv/config", "./build/index.js"]