feat: task trash, triage trash and retention settings for every area; admin can forbid keeping things for good

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

frontend/src/lib/api.ts

@@ -4,6 +4,8 @@ import {
   DashboardStats,
   Document,
   TrashedDocument,
+  TrashedTask,
+  Retention,
   JournalDay,
   PushDevice,
   BackupFile,
@@ -302,6 +304,7 @@ export const api = {
     notificationSettings?: NotificationSettings;
     doneRetentionDays?: number;
     voiceInput?: '' | 'browser';
+    retention?: Retention;
   }): Promise<User> {
     return request<User>('/api/v1/auth/settings', {
       method: 'PATCH',
@@ -479,6 +482,24 @@ export const api = {
     return request<{ deleted: number }>('/api/v1/tasks/clear-done', { method: 'POST', body: JSON.stringify({ taskListId }) });
   },
 
+  // Task trash: deleted tasks, cleared and automatically cleaned-up completed ones
+  async getTaskTrash(taskListId = ''): Promise<TrashedTask[]> {
+    const q = taskListId ? `?taskListId=${encodeURIComponent(taskListId)}` : '';
+    return request<TrashedTask[]>(`/api/v1/tasks/trash${q}`);
+  },
+
+  async restoreTrashedTask(id: string): Promise<Thought> {
+    return request<Thought>(`/api/v1/tasks/trash/${id}/restore`, { method: 'POST' });
+  },
+
+  async purgeTrashedTask(id: string): Promise<{ deleted: boolean }> {
+    return request<{ deleted: boolean }>(`/api/v1/tasks/trash/${id}`, { method: 'DELETE' });
+  },
+
+  async emptyTaskTrash(taskListId: string): Promise<{ deleted: number }> {
+    return request<{ deleted: number }>('/api/v1/tasks/trash/empty', { method: 'POST', body: JSON.stringify({ taskListId }) });
+  },
+
   async purgeDiscarded(): Promise<{ purged: number }> {
     return request<{ purged: number }>('/api/v1/thoughts/discarded/purge', { method: 'DELETE' });
   },

frontend/src/lib/due.ts

@@ -48,3 +48,10 @@ export const formatDue = (due: string | undefined, now: Date = new Date()): stri
   else label = `${pad(d)}.${pad(m)}.${y}`;
   return time ? `${label}, ${time}` : label;
 };
+
+/** When something went to a trash, e.g. "01.11.2026, 14:05". */
+export const formatDeletedAt = (iso: string) => {
+  const d = new Date(iso);
+  if (Number.isNaN(d.getTime())) return '';
+  return d.toLocaleString('de-DE', { day: '2-digit', month: '2-digit', year: 'numeric', hour: '2-digit', minute: '2-digit' });
+};

frontend/src/lib/types.ts

@@ -115,6 +115,9 @@ export interface User {
   doneRetentionDays?: number;
   // Voice input: '' = the server's Whisper (default), 'browser' = the browser's recognition
   voiceInput?: '' | 'browser';
+  // How long finished and deleted things are kept, in days (0 = for good; only when allowed)
+  retention?: Retention;
+  retentionNeverAllowed?: boolean;
   organizationId?: string;
   createdAt: string;
 }
@@ -293,6 +296,9 @@ export interface SystemSettings {
   backupEnabled?: boolean;
   backupTime?: string;
   backupRetentionDays?: number;
+  // People may keep finished and deleted things for good ("nie"); fixed when set via RETENTION_ALLOW_NEVER
+  retentionAllowNever?: boolean;
+  retentionNeverViaEnv?: boolean;
 }
 
 /** One file of a server backup listing. */
@@ -382,6 +388,26 @@ export interface JournalDay {
   empty: boolean;
 }
 
+/** Delays in days per area (Kontoeinstellungen → Aufbewahrung); 0 = keep for good. */
+export interface Retention {
+  doneTasks: number;
+  taskTrash: number;
+  triageTrash: number;
+  noteTrash: number;
+  listDone: number;
+}
+
+/** A deleted task waiting in the task trash. */
+export interface TrashedTask {
+  id: string;
+  content: string;
+  taskListId: string;
+  isCompleted: boolean;
+  trashedAt: string;
+  trashedBy: string;
+  canEdit: boolean;
+}
+
 export interface TrashedDocument {
   id: string;
   title: string;