fix(deploy): stage blackbox config + derive bare Grafana SMTP from-address

Two contour-deploy failures from PR4: (1) the deploy did not stage deploy/blackbox/, so
blackbox_exporter crash-looped on a missing config mount — add blackbox to the ci.yaml cp
and the prod-deploy tar; (2) Grafana rejects the 'Name <addr>' From form the backend go-mail
accepts and validates it even when SMTP is disabled, crash-looping Grafana — the deploy now
splits SMTP_RELAY_SERVICE_FROM into a bare GF_SMTP_FROM_ADDRESS + GRAFANA_SMTP_FROM_NAME
(handles both display and bare forms). Verified the sed split + compose render.

deploy/.env.example

@@ -51,7 +51,7 @@ PUBLIC_BASE_URL=                       # required when SMTP_RELAY_HOST is set (e
 # port (it can't do the backend's implicit TLS), GRAFANA_SMTP_PORT. All empty = off.
 SMTP_RELAY_ADMIN_FROM=                 # backend admin-alert From (e.g. alerts@erudit-game.ru)
 ADMIN_EMAIL=                           # backend admin-alert recipient(s), comma-separated
-SMTP_RELAY_SERVICE_FROM=               # Grafana alert From (e.g. grafana@erudit-game.ru)
+SMTP_RELAY_SERVICE_FROM=               # Grafana alert From; the deploy derives a bare address for Grafana (it rejects "Name" <addr>)
 SERVICE_EMAIL=                         # Grafana alert recipient(s), comma-separated
 GRAFANA_SMTP_PORT=                     # Grafana STARTTLS port on SMTP_RELAY_HOST (Selectel: 1126)
 GF_SMTP_ENABLED=false                  # set true to enable Grafana alert emails