Recherche abbrechen + Chats löschen (mit Aufräumen) + Truncation-Fix

- Manueller Abbruch: POST /api/sessions/:id/abort (nur Owner), AbortController
  für laufende Jobs (auch mitten im API-Stream), cancelQueued für wartende,
  ⛔-Button in der Activity-Bar, 'abgebrochen'-Event + History-Eintrag
- Chats löschen: 🗑-Button in der Sidebar mit Bestätigung, Ownership-Check
  (vorher konnte jeder fremde Chats löschen), löscht jetzt auch Messages
  und Dashboard-Dateien (HTML/GPX/tour.json) mit
- Truncation-Fix: finish_reason 'length' wird erkannt (sichtbarer Fehler
  statt leerer Abschluss), max_tokens auf 131072 (GLM-Max), 10-Min-Timeout
  gegen hängende Streams

public/app.js

@@ -62,18 +62,52 @@ function renderSessions() {
         : s.status === 'done'
           ? '<span class="w-2 h-2 rounded-full bg-emerald-400 inline-block mr-2"></span>'
           : '<span class="w-2 h-2 rounded-full bg-slate-500 inline-block mr-2"></span>';
+    const row = document.createElement('div');
+    row.className = 'group relative';
     const btn = document.createElement('button');
     btn.className = `w-full text-left px-3 py-2 rounded-lg text-sm flex items-start gap-1 ${
       active ? 'bg-blue-600/20 text-blue-300' : 'hover:bg-slate-800'
     }`;
-    btn.innerHTML = `${dot}<span class="truncate">${escapeHtml(s.title)}</span>`;
+    btn.innerHTML = `${dot}<span class="truncate flex-1">${escapeHtml(s.title)}</span>`;
     btn.onclick = () => openSession(s.id);
-    list.appendChild(btn);
+    const del = document.createElement('button');
+    del.className =
+      'absolute right-1 top-1/2 -translate-y-1/2 w-6 h-6 rounded text-xs text-slate-500 hover:text-red-400 hover:bg-slate-700 opacity-0 group-hover:opacity-100';
+    del.textContent = '🗑';
+    del.title = 'Chat löschen';
+    del.onclick = (e) => {
+      e.stopPropagation();
+      deleteSession(s.id);
+    };
+    row.append(btn, del);
+    list.appendChild(row);
   }
   const qs = state.sessions.find((s) => s.job === 'running' || s.job === 'queued');
   $('queueStatus').classList.toggle('hidden', !qs);
 }
 
+async function deleteSession(id) {
+  const s = state.sessions.find((x) => x.id === id);
+  if (!confirm(`Chat „${s?.title || '…'}“ wirklich löschen? Das zugehörige Dashboard wird mit gelöscht.`)) return;
+  const res = await fetch(`/api/sessions/${id}`, { method: 'DELETE' });
+  if (!res.ok) {
+    addToolLine('⚠️', 'Löschen fehlgeschlagen');
+    return;
+  }
+  if (state.current?.id === id) {
+    state.stream?.close();
+    state.stream = null;
+    state.streamingEl = null;
+    state.current = null;
+    hideActivity();
+    const next = state.sessions.find((x) => x.id !== id);
+    if (next) await openSession(next.id);
+    else await newSession();
+  } else {
+    await loadSessions();
+  }
+}
+
 // ---------------------------------------------------------------------------
 // Chat-Rendering
 // ---------------------------------------------------------------------------
@@ -187,6 +221,8 @@ function showActivity() {
   $('activityLog').classList.add('hidden');
   $('toggleLog').textContent = 'Details zeigen';
   state.activityShown = true;
+  $('abortBtn').classList.remove('hidden');
+  $('abortBtn').disabled = false;
 }
 
 function setActivity(text, icon = '') {
@@ -202,15 +238,29 @@ function logActivity(text) {
 
 function hideActivity() {
   $('activityBar').classList.add('hidden');
+  $('abortBtn').classList.add('hidden');
   state.activityShown = false;
 }
 
+async function abortResearch() {
+  if (!state.current) return;
+  $('abortBtn').disabled = true;
+  setActivity('Breche Recherche ab…', '⛔');
+  try {
+    await fetch(`/api/sessions/${state.current.id}/abort`, { method: 'POST' });
+  } catch {
+    $('abortBtn').disabled = false;
+  }
+}
+
 $('toggleLog').onclick = () => {
   const log = $('activityLog');
   const hidden = log.classList.toggle('hidden');
   $('toggleLog').textContent = hidden ? 'Details zeigen' : 'Details verbergen';
 };
 
+$('abortBtn').onclick = abortResearch;
+
 // ---------------------------------------------------------------------------
 // SSE-Stream
 // ---------------------------------------------------------------------------
@@ -286,6 +336,13 @@ function connectStream(sessionId) {
     $('sendBtn').disabled = false;
   });
 
+  es.addEventListener('aborted', () => {
+    addToolLine('⛔', 'Recherche abgebrochen.');
+    hideActivity();
+    loadSessions();
+    $('sendBtn').disabled = false;
+  });
+
   es.addEventListener('error', (e) => {
     if (!e.data) return;
     const d = JSON.parse(e.data);

public/index.html

@@ -57,6 +57,8 @@
       <div id="activityLine" class="flex items-center gap-2">
         <span class="inline-block w-3 h-3 border-2 border-blue-500 border-t-transparent rounded-full animate-spin"></span>
         <span id="activityText">Starte…</span>
+        <button id="abortBtn" type="button" title="Recherche abbrechen"
+                class="ml-auto hidden text-xs px-2 py-1 rounded-lg bg-red-600/15 text-red-400 hover:bg-red-600/30">⛔ Abbrechen</button>
       </div>
       <div id="activityLog" class="hidden mt-1 max-h-32 overflow-y-auto text-xs text-slate-400 space-y-0.5"></div>
       <button id="toggleLog" class="text-xs text-blue-400 mt-1">Details zeigen</button>