Implement /packages/backend-node to match provided spec:\n- exact package.json deps/devDeps/scripts\n- tsconfig target ES2020 module CommonJS outDir dist strict true\n- src/index.ts routes, sqlite schema+seed, websocket relay/challenge auth behavior\n- fix compile issues\n- run npm install and npm run build in package dir\n\nAcceptance: build succeeds and outputs captured.
Implement /packages/backend-node to match provided spec:\n- exact package.json deps/devDeps/scripts\n- tsconfig target ES2020 module CommonJS outDir dist strict true\n- src/index.ts routes, sqlite schema+seed, websocket relay/challenge auth behavior\n- fix compile issues\n- run npm install and npm run build in package dir\n\nAcceptance: build succeeds and outputs captured.