Desktop connection SaaS: config, billing, team support (#5768)

Co-authored-by: James Brunton <[email protected]>
Co-authored-by: James Brunton <[email protected]>

frontend/vite.config.ts

@@ -22,6 +22,7 @@ export default defineConfig(({ mode }) => {
     const requiredEnvVars = [
       'VITE_SAAS_SERVER_URL',
       'VITE_SUPABASE_PUBLISHABLE_DEFAULT_KEY',
+      'VITE_SAAS_BACKEND_API_URL',
     ];
 
     const missingVars = requiredEnvVars.filter(varName => !env[varName]);