NixOS consumers (webapp-module's hub build, server-deploy's
standalones module) bake VITE_* env vars into the bundle at build
time: VITE_BASE_PATH for path-mounted standalones,
VITE_LNBITS_BASE_URL / VITE_NOSTR_RELAYS / VITE_LIGHTNING_DOMAIN /
etc. for per-deployment service URLs.
extraEnv is merged on top of the brand kit + sandbox defaults
(BRAND_DIR, BRAND_APP, CI). Brand-controlled vars (VITE_APP_NAME via
brand.name) stay strict — the vite configs internally set
process.env.VITE_APP_NAME from brand.json after the derivation
starts, so an extraEnv attempt at VITE_APP_NAME is a no-op (by
design, per #99 strict-from-the-start). Per-host name customization
flows through per-host brandDir, not env vars.
Verified VITE_BASE_PATH=/events/ via extraEnv emits hrefs prefixed
with /events/ in the built events.html.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
