Modernize frontend and centralize branding

src/config/api.js

@@ -1,17 +1,19 @@
 /**
  * API / WebSocket base URLs for local dev and production.
- * Set REACT_APP_API_URL and REACT_APP_WS_URL in .env (see .env.example).
+ * Set VITE_API_URL, VITE_WS_URL, and VITE_SITE_URL in .env (see .env.example).
  */
+import branding from '../branding';
+
 const trimTrailingSlash = (url) => (url || '').replace(/\/$/, '');
 
 export const API_BASE_URL = trimTrailingSlash(
-  process.env.REACT_APP_API_URL || 'https://anchorhost.eu'
+  import.meta.env.VITE_API_URL || branding.siteUrl
 );
 
 export const WS_BASE_URL = trimTrailingSlash(
-  process.env.REACT_APP_WS_URL || 'wss://anchorhost.eu/ws'
+  import.meta.env.VITE_WS_URL || `wss://${branding.domain}/ws`
 );
 
 export const SITE_BASE_URL = trimTrailingSlash(
-  process.env.REACT_APP_SITE_URL || API_BASE_URL
+  import.meta.env.VITE_SITE_URL || branding.siteUrl
 );