Fix/status page forwarded host routing

[aiokaizen]

• Fixes custom-domain routing for self-hosted status pages behind a reverse proxy.
• The status-page app was reading x-forwarded-host, but then still derived subdomain from url.host.
• In self-hosted Docker deployments, url.host is the container host (0.0.0.0:3000 / localhost:3000), not the public domain.
• That caused the resolved routing prefix to be overwritten with the container host, breaking custom-domain routing.
• Result: requests for domains like status.pinbridge.io could fall back to the public root/theme-builder flow instead of the intended status page.
• This patch introduces effectiveHost = x-forwarded-host ?? url.host and uses it consistently for:
  • hostname splitting
  • subdomain detection
  • .vercel.app checks
• Updated files:
  • apps/status-page/src/proxy.ts
  • apps/status-page/src/lib/domain.ts
• This is especially important for self-hosted setups behind nginx or another reverse proxy that forwards the public host.
• No version changes included.

[vercel]

@aiokaizen is attempting to deploy a commit to the OpenStatus Team on Vercel.

A member of the Team first needs to authorize it.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
openstatus-dashboard	Ready	Preview, Comment	Mar 13, 2026 10:44am
openstatus-status-page	Ready	Preview, Comment	Mar 13, 2026 10:44am
openstatus-web	Ready	Preview, Comment	Mar 13, 2026 10:44am