fix(traefik): Fix HostRegexp YAML escaping for subdomain routing

In YAML single-quoted strings, backslashes are literal characters.
'\\.' was being interpreted as two backslashes + dot, not as an
escaped dot in the regex.

Changed from '\\.smoothschedule\\.com' to '\.smoothschedule\.com'

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

smoothschedule/compose/production/traefik/traefik.yml

@@ -123,7 +123,7 @@ 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(`.+\\.smoothschedule\\.com`)'
+      rule: 'HostRegexp(`.+\.smoothschedule\.com`)'
       priority: 1
       entryPoints:
         - web-secure