Wire viewer-frontend Vitest into Gitea Actions, centralize DEV base URLs
in env-defaults.json, expand playkit API catalog specs, and land auth/mail
flows plus verify-email public-host redirect and idle-logout e2e hooks.
Add an e2e/ Playwright harness (via @levkin/playkit) that smoke-tests
the public DEV host: login page loads, sign-out never redirects to a
LAN host, FastAPI /health responds, and forgot-password mail lands in
Mailtrap with a public reset link (Kolby #56/#57 regressions).
Wire it into Gitea Actions as a new `e2e` job (self-hosted runner,
Chromium via Playwright), gated behind the existing skip-ci-check.
Add npm root scripts (install:e2e, test:e2e) and gitignore e2e build
artifacts (node_modules, reports, .env).
