The nginx block is plain http; certbot adds the TLS server block and the
redirect itself. It sets X-Forwarded-Proto, which is load-bearing: the
app compares the browser's Origin against the URL it believes it is
serving, and without that header it thinks it is on http while the
browser says https, decides every save is cross-site and drops the
session.
Upstream's README is kept as README.nullboard.md.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UU1vyTHj3uE9PJYSxRxwkU
