Slice 1+3 (c4fbd2b) introduced PUBLIC_URL as the env var name for the
public-facing origin used to construct invite-accept URLs. The README
has long documented APP_URL as the canonical name for this concept
(used for Stripe callbacks in the existing codebase). The new code
should have read APP_URL from the start; PUBLIC_URL was unintentional
naming drift.
Caught during prod-deploy survey on 2026-05-17: APP_URL was set on the
production systemd unit and documented in the README, but read by no
code path on origin/main. PUBLIC_URL was read by slice-1 code but set
nowhere. The bug was masked in 99% of cases by the request-derived
fallback (${req.protocol}://${req.get('host')}) which produces the
correct URL when invites are triggered from browsers behind Cloudflare.
It would have manifested for any future non-browser-triggered invite
path.
README updated to note APP_URL covers both Stripe callbacks and
invite-accept URL generation.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>