SSR alert mail recipients maintainable in the site settings

New site setting vitec.ssr.alertEmails (Site Management, Settings, VITEC; one address per entry). vitec:ssr-health reads the recipients from there, invalid entries are skipped and logged, SSR_ALERT_EMAIL in the env file stays as fallback. The cockpit shows the recipients in the live band. Pre-filled with the address that was in the env file.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

config/sites/vitec/settings.yaml

@@ -23,3 +23,5 @@ vitec.ssr.enabled: true
 # Shell-Seiten (Produkt-/News-/Story-Detail-Container) nicht in die XML-Sitemap
 # aufnehmen; 106 = alter /en/news-Ast (noindex-Duplikate). SEO-Audit 2026-11-09.
 seo.sitemap.pages.excludePagesRecursive: '10,21,26,106'
+vitec.ssr.alertEmails:
+  - info@evomedien.de