Recent ghcr.io/hkuds/lightrag releases validate auth config at startup
and refuse to boot with `TOKEN_SECRET must be explicitly set to a
non-default value when AUTH_ACCOUNTS is configured`. The container
crash-looped and Caddy returned 502.
Generate LIGHTRAG_TOKEN_SECRET (secret:64) and pass it as TOKEN_SECRET
to the lightrag container. Existing installations pick it up on
`make update` via 03_generate_secrets.sh --update.
Release 1.4.3.
Closes#60
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>