Fix: Entferne window-Referenz und verbessere Fehlermeldungen

lib/wg-api.ts

@@ -67,12 +67,20 @@ export class WgApiClient {
 
   private async request<T>(endpoint: string, options: RequestInit = {}): Promise<T> {
     // Liste möglicher Backend-URLs zum Ausprobieren
+    // Hinweis: Port 51821 ist der Standard-Port für wg-easy Web-UI
+    // Wenn das Backend auf einem anderen Port läuft, muss WG_API_URL als Environment Variable gesetzt werden
     const possibleUrls = [
       this.baseUrl, // Zuerst die konfigurierte URL versuchen
       'http://localhost:51821',
       'http://127.0.0.1:51821',
+      'http://localhost:51820', // Alternative Port
       'http://wg-easy:51821',
+      'http://wg-easy:51820',
       'http://srv-captain--wg-easy:51821',
+      'http://srv-captain--wg-easy:51820',
+      // Versuche auch mögliche CapRover Service-Namen
+      'http://srv-captain--corex-wg-easy:51821',
+      'http://srv-captain--corex-wg-easy:51820',
     ]
 
     let lastError: Error | null = null
@@ -129,8 +137,14 @@ export class WgApiClient {
       }
     }
 
-    // All URLs failed
-    throw new Error(`Failed to connect to WG API. Tried: ${possibleUrls.join(', ')}. Last error: ${lastError?.message || 'Unknown error'}`)
+    // All URLs failed - provide helpful error message
+    const triedUrls = possibleUrls.filter((url, index, self) => self.indexOf(url) === index) // Remove duplicates
+    throw new Error(
+      `Failed to connect to WG API Backend. ` +
+      `Tried URLs: ${triedUrls.join(', ')}. ` +
+      `Last error: ${lastError?.message || 'Unknown error'}. ` +
+      `Please ensure the wg-easy backend is running and set WG_API_URL environment variable if it's on a different URL/port.`
+    )
   }
 
   async getStats(): Promise<WgStats> {