Serve resilient launch cover independently of application upstream

PRODUCTION.md

@@ -49,3 +49,16 @@ root folders, invite policy and notification rules in admin settings before use.
 - Retrieve `/home/zak/magent-production/bootstrap-admin.json` securely on
   AMS-DEV01. Sign in at `/login`, then open `/admin` while the cover is active.
 - No SMTP message was sent as part of validation. Background jobs remain paused.
+
+## Cover resilience update
+
+The application host subsequently became unreachable over TCP from Caddy (both
+3100 and 3200 timed out, despite responding to ping). The cover is now served
+directly by Caddy from `/var/lib/caddy/magent-cover/index.html`, sourced from
+`docker/coming-soon.html`, for `/`, `/coming-soon` and `/coming-soon/`.
+It needs no application server, JavaScript, API or external assets.
+Other paths retain the production reverse proxy. Full launch now also requires
+removing the `@landing`/static `handle` block from the production Caddy site once
+upstream connectivity is stable; the environment switch alone is insufficient.
+Pre-static configuration backup:
+`/etc/caddy/Caddyfile.bak-magent-static-20260907T0145`.