Stalwart's --init only runs when config.toml is absent, but ours
is mounted from a ConfigMap so no admin account was ever created.
Use the fallback-admin config with %{env:ADMIN_SECRET}% referencing
a stalwart-admin K8s secret. This survives pod restarts without
depending on RocksDB-stored credentials.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>