Helmet's defaults are designed for HTTPS-only deployments. Two directives
were actively breaking plain-HTTP self-hosted instances:
- upgrade-insecure-requests: causes browsers to upgrade all JS/CSS/asset
fetches to HTTPS → ERR_SSL_PROTOCOL_ERROR → completely blank page
- Strict-Transport-Security: permanently instructs browsers to refuse HTTP
for 1 year, even after the header is removed from the server
Also handle docker socket GID=0 (root:root) edge case in entrypoint and
add [entrypoint] diagnostic log lines for easier debugging.
SaelixCode