feat: auto detect callback url (#583)

Co-authored-by: Elias Schneider <login@eliasschneider.com>

frontend/src/lib/types/oidc.type.ts

@@ -7,7 +7,7 @@ export type OidcClientMetaData = {
 };
 
 export type OidcClient = OidcClientMetaData & {
-	callbackURLs: [string, ...string[]];
+	callbackURLs: string[]; // No longer requires at least one URL
 	logoutCallbackURLs: string[];
 	isPublic: boolean;
 	pkceEnabled: boolean;