feat(server): support multiple hosts in one deployment (#12950)

close CLOUD-233



#### PR Dependency Tree


* **PR #12950** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **New Features**
* Added support for configuring multiple server hosts across backend and
frontend settings.
* Enhanced deployment and Helm chart configuration to allow specifying
multiple ingress hosts.
* Updated admin and configuration interfaces to display and manage
multiple server hosts.

* **Improvements**
* Improved URL generation, OAuth, and worker service logic to
dynamically handle requests from multiple hosts.
  * Enhanced captcha verification to support multiple allowed hostnames.
* Updated frontend logic for platform-specific server base URLs and
allowed origins, including Apple app domains.
  * Expanded test coverage for multi-host scenarios.

* **Bug Fixes**
* Corrected backend logic to consistently use dynamic base URLs and
origins based on request host context.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/oauth/controller.ts

@@ -142,7 +142,7 @@ export class OAuthController {
           provider: rawState.provider,
         })
       );
-      clientUrl.searchParams.set('server', this.url.origin);
+      clientUrl.searchParams.set('server', this.url.requestOrigin);
 
       return res.redirect(
         this.url.link('/open-app/url?', {