Fix console showing endless loading when logs are empty

Changed logs state initialization from empty string to null to properly
distinguish between "not yet loaded" and "loaded but empty" states.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

gsm-frontend/src/components/ServerDetailModal.jsx

@@ -10,7 +10,7 @@ export default function ServerDetailModal({ server, onClose, onUpdate }) {
   const [activeTab, setActiveTab] = useState('overview')
   const [rconCommand, setRconCommand] = useState('')
   const [rconHistory, setRconHistory] = useState([])
-  const [logs, setLogs] = useState('')
+  const [logs, setLogs] = useState(null)
   const logsRef = useRef(null)
   const rconRef = useRef(null)
 
@@ -299,7 +299,7 @@ export default function ServerDetailModal({ server, onClose, onUpdate }) {
                 ref={logsRef}
                 className="terminal rounded h-96 overflow-y-auto p-4 font-mono text-xs text-[#00ff41]/80 whitespace-pre-wrap"
               >
-                {logs || 'Loading...'}
+                {logs === null ? 'Loading...' : (logs || 'Keine Logs verfügbar')}
               </div>
             </div>
           )}

gsm-frontend/src/pages/ServerDetail.jsx

@@ -31,7 +31,7 @@ export default function ServerDetail() {
   const [activeTab, setActiveTab] = useState('overview')
   const [rconCommand, setRconCommand] = useState('')
   const [rconHistory, setRconHistory] = useState([])
-  const [logs, setLogs] = useState('')
+  const [logs, setLogs] = useState(null)
   const [whitelistPlayers, setWhitelistPlayers] = useState([])
   
   const [whitelistInput, setWhitelistInput] = useState('')
@@ -517,7 +517,7 @@ const formatUptime = (seconds) => {
               ref={logsRef}
               className="terminal p-4 logs-container text-xs text-neutral-300 whitespace-pre-wrap"
             >
-              {logs || 'Laden...'}
+              {logs === null ? 'Laden...' : (logs || 'Keine Logs verfügbar')}
             </div>
 
             {/* RCON History */}