fixed, aria reuse old session, and reload chat

diagnostic/index.html

@@ -471,6 +471,7 @@
       ws.onopen = () => {
         addLog('info', 'browser', 'Verbunden mit Diagnostic Server');
         send({ action: 'get_active_session' });
+        send({ action: 'load_chat_history' });
       };
       ws.onclose = () => {
         addLog('warn', 'browser', 'Verbindung zum Diagnostic Server verloren — Reconnect in 2s');
@@ -567,6 +568,24 @@
           showDockerLogs(msg);
           return;
         }
+        // Chat-History (nach F5 / Reconnect)
+        if (msg.type === 'chat_history') {
+          if (msg.messages && msg.messages.length > 0) {
+            chatBox.innerHTML = '';
+            for (const m of msg.messages) {
+              const el = document.createElement('div');
+              el.className = `chat-msg ${m.type}`;
+              const escaped = escapeHtml(m.text);
+              const linked = linkifyText(escaped);
+              const time = m.ts ? new Date(m.ts).toLocaleTimeString('de-DE') : '?';
+              el.innerHTML = `${linked}<div class="meta">${escapeHtml(m.meta)} — ${time}</div>`;
+              chatBox.appendChild(el);
+            }
+            chatBox.scrollTop = chatBox.scrollHeight;
+          }
+          return;
+        }
+
         // Session + Brain Viewer
         if (msg.type === 'sessions_list') { renderSessions(msg); return; }
         if (msg.type === 'session_detail') { renderSessionDetail(msg); return; }