Materialise /var/lib/archipelago/secrets/btcpay-lnd-connection
(type=lnd-rest;server=https://lnd:8080/;macaroon=<hex>;certthumbprint=<sha256>)
in ensure_app_secrets before btcpay-server env resolution.
The macaroon travels inline as hex because LND's datadir is owned by its
container subuid (100999) — bind-mounting it into btcpay's userns EACCESes.
Reads the macaroon via the existing read_file_as_root sudo fallback; pins the
TLS cert by DER SHA256 thumbprint and rewrites on cert rotation. No-op while
LND is absent (btcpay's secret_env entry is optional), and generation errors
log-and-continue so btcpay never fails to start over this.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>