feat: T1 scaffold — package.json, tsconfig (backend+web), vitest, dirs
- All deps declared once (express5, ws, node-pty, @xterm/xterm6, addon-fit;
dev: typescript6, tsx, vitest4, @types/node|ws|express)
- postinstall chmod +x node-pty spawn-helper (prebuild ships it non-exec → posix_spawnp fails)
- node-pty verified: require + real PTY spawn (exitCode 0)
- npm test passes with no tests (passWithNoTests)
- tsconfig.web.json type-checks frontend; browser bundling strategy still TBD (see log)
T1 of docs/PLAN.md
b126cf0e42