fix: load SMTP via secret files on submissions:465

Env-based notifier creds were unreliable; use secrets/smtp_*.txt, RFC5322 sender, and implicit TLS to 0012.de Plesk.

Co-authored-by: Cursor <cursoragent@cursor.com>

.env.example

@@ -1,15 +1,16 @@
 # Copy to .env on the deploy host. Never commit .env.
-# SMTP values: same as ~/git/froxxxy/0012/server.env (Plesk mail)
 
 TZ=Europe/Berlin
 
-# --- Authelia crypto (generate on deploy; see README) ---
-# Prefer secret files under ./secrets/ (recommended). If you use env instead:
-# AUTHELIA_IDENTITY_VALIDATION_RESET_PASSWORD_JWT_SECRET=
-# AUTHELIA_SESSION_SECRET=
-# AUTHELIA_STORAGE_ENCRYPTION_KEY=
+# Optional: Authelia log level (info|debug|trace)
+# AUTHELIA_LOG_LEVEL=info
 
-# --- SMTP (0012.de Plesk) ---
-AUTHELIA_NOTIFIER_SMTP_USERNAME=admin@0012.de
-AUTHELIA_NOTIFIER_SMTP_PASSWORD=
-AUTHELIA_NOTIFIER_SMTP_SENDER=Authelia <monitor@0012.de>
+# --- SMTP credentials (0012.de Plesk) ---
+# Authelia reads these from secret files (not from env):
+#   secrets/smtp_username.txt   e.g. auth@0012.de
+#   secrets/smtp_password.txt
+#   secrets/smtp_sender.txt     e.g. Authelia <auth@0012.de>
+# Create them on the server (see README). Keep this .env for your own notes if useful:
+SMTP_USER=auth@0012.de
+SMTP_PASSWORD=
+SMTP_SENDER=Authelia <auth@0012.de>