chore(deploy): strip infra commentary from asset/ config files

These ship in a public repo; topology narration in nginx, systemd,
firewalld, and env templates is gratuitous. Keep the config terse —
directives speak for themselves.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

asset/config/api.env.tmpl

@@ -1,6 +1,3 @@
-# /etc/moments/api.env — rendered by deploy.sh, do not edit on the host.
-# {{HOSTNAME}} resolves to the target host's FQDN at deploy time.
-
 JOURNAL_STREAM=1
 RUST_LOG=info,sqlx=warn,tower_http=info