fix(#25983): update theme default to auto (#25985)

Signed-off-by: Elton de Boer <elton@playgroundtech.io>

USERS.md

@@ -298,6 +298,7 @@ Currently, the following organizations are **officially** using Argo CD:
 1. [Pismo](https://pismo.io/)
 1. [PITS Globale Datenrettungsdienste](https://www.pitsdatenrettung.de/)
 1. [Platform9 Systems](https://platform9.com/)
+1. [Playground Tech](https://playgroundgroup.io)
 1. [Polarpoint.io](https://polarpoint.io)
 1. [Pollinate](https://www.pollinate.global)
 1. [PostFinance](https://github.com/postfinance)

ui/src/app/shared/services/view-preferences-service.ts

@@ -175,7 +175,7 @@ const DEFAULT_PREFERENCES: ViewPreferences = {
     hideBannerContent: '',
     hideSidebar: false,
     position: '',
-    theme: 'light'
+    theme: 'auto'
 };
 
 export class ViewPreferencesService {