feat(mcp): delete tasks, create task lists and lists, agent badge; export/import settings category

New MCP tools delete_task (tasks:write), create_task_list (tasks:write) and create_list
(lists:write); list_task_lists now returns the board columns so agents know the valid
kanbanStatus values. Task deletion is a shared helper (deleteTask) for REST and MCP.

Tasks and list items get agent_mark (migration 12): "created" when an agent adds them via MCP,
"edited" when an agent changes them; a change by the user clears it. The new AgentBadge shows
"KI" / "KI geändert" in task rows, Kanban cards, the task detail, the inbox and lists.

Settings: export and import move out of "Webhooks, KI-Agenten & Export" into their own
category "Export & Import". Docs, help, README and changelog updated; v0.29.0.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/features/triage/TasksView.tsx

@@ -35,6 +35,7 @@ import { useKanbanTouchDrag } from './useKanbanTouchDrag';
 import { api, triggerHaptic } from '../../lib/api';
 import { UnifiedShareModal } from '../../components/UnifiedShareModal';
 import { TaskDetailModal } from './TaskDetailModal';
+import { AgentBadge } from '../../components/AgentBadge';
 import { ManageColumnsModal, DEFAULT_KANBAN_COLUMNS } from './ManageColumnsModal';
 import { AvatarStack, AvatarPerson } from '../../components/AvatarStack';
 import { CountBadge } from '../../components/CountBadge';
@@ -287,7 +288,7 @@ export const TasksView: React.FC<TasksViewProps> = ({
         }
       } else if (msg.event === 'TASK_REORDERED') {
         loadData();
-      } else if (msg.event === 'TASK_LIST_UPDATED' || msg.event === 'TASK_LIST_DELETED') {
+      } else if (msg.event === 'TASK_LIST_CREATED' || msg.event === 'TASK_LIST_UPDATED' || msg.event === 'TASK_LIST_DELETED') {
         // Payload only carries the list ID; reload so permissions reflect this user's view
         api.getTaskLists().then((lists) => setTaskLists(Array.isArray(lists) ? lists : [])).catch(() => {});
       }
@@ -1352,6 +1353,7 @@ export const TasksView: React.FC<TasksViewProps> = ({
                   <span>Webhook</span>
                 </span>
               )}
+              <AgentBadge mark={task.agentMark} />
 
               {/* Note indicator */}
               {task.notes && (
@@ -2435,6 +2437,7 @@ export const TasksView: React.FC<TasksViewProps> = ({
                               <span>Webhook</span>
                             </span>
                           )}
+                          <AgentBadge mark={task.agentMark} size="xs" />
                           {task.dueDate && (
                             <span
                               className={`inline-flex items-center gap-0.5 text-[9px] ${!task.isCompleted && isOverdue(task.dueDate) ? 'text-status-err font-semibold' : 'text-muted'}`}