web-e2e started the backend through `pnpm nx run web-backend:serve`. Nx
run-commands spawns its command in a detached process group, so
Playwright's process-group SIGKILL reached only pnpm/nx and the tsx
server was reparented and kept port 3333. Launch it as a single
`node --import tsx` process with the serve target's env, as #1710 did
for the mock servers.
WEB_BACKEND_PORT relocates the backend for side-by-side worktrees, and
a web-backend guard spec rejects an Nx launch or env drift from the
serve target. web:serve is unaffected: the Angular dev-server runs
inside the Nx process and stops with it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
