SMTP: Add host, port, username, sender, and password fields to the
Authelia configuration. Uses modern address format (submission:// for
STARTTLS on 587, smtps:// for implicit TLS on 465) with explicit TLS
server name. Falls back to filesystem notifier when SMTP is not
configured.
Fixes: Config changes now persist before attempting service restart,
so a restart failure (e.g. bad SMTP credentials) no longer prevents
saving. The specific Authelia error is extracted from the journal and
shown in the UI.
Frontend: SMTP fields added to the Authentication config card. Form
no longer continuously resets from server state while user is editing.
OIDC client edit UI added (pencil icon).
Paul Payne
134c01fe5e