Behebt Demo-Modus: committete Env-Dateien und Project-ID-Fallback

.env.development/.env.production und zentraler isDemoMode verhindern
leere VITE_APPWRITE_PROJECT_ID nach git clone ohne lokale .env.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/hooks/useWorkorders.js

@@ -1,7 +1,7 @@
 import { useState, useEffect, useCallback } from 'react'
-import { databases, DATABASE_ID, COLLECTIONS, Query, ID } from '../lib/appwrite'
+import { databases, DATABASE_ID, COLLECTIONS, Query, ID, isDemoMode } from '../lib/appwrite'
 
-const DEMO_MODE = !import.meta.env.VITE_APPWRITE_PROJECT_ID
+const DEMO_MODE = isDemoMode
 
 // Demo data for testing without Appwrite
 const lastWeek = new Date(Date.now() - 7 * 24 * 60 * 60 * 1000)