fix(traefik): Simplify HTTP HostRegexp pattern

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

smoothschedule/compose/production/traefik/traefik.yml

@@ -138,7 +138,7 @@ http:
     # Routes to nginx which serves the frontend SPA and proxies /api/ to Django
     # Low priority (1) ensures specific domain routers match first
     subdomain-router:
-      rule: 'HostRegexp(`^[a-z0-9-]+\\.smoothschedule\\.com$`)'
+      rule: 'HostRegexp(`.+\\.smoothschedule\\.com`)'
       priority: 1
       entryPoints:
         - web-secure