feat(page): temporary notes — auto-trash after X hours unless made permanent (#201)

"Temporary notes" with a death timer: created via a dedicated hourglass button
in the space-tree header, a note auto-moves to Trash after a configurable X
hours (default 24) unless explicitly made permanent ("structure or die").

Reuses existing mechanisms, mirroring is_template and the trash-cleanup job:
- New nullable column pages.temporary_expires_at (NULL = permanent; non-NULL =
  frozen deadline) + partial index for the sweep; workspace column
  temporary_note_hours (default via DEFAULT_TEMPORARY_NOTE_HOURS = 24).
- create-page DTO `temporary` flag; the deadline is frozen at creation so later
  setting changes never reschedule existing notes.
- POST /pages/toggle-temporary (mirror of toggle-template): arm/clear the timer,
  CASL-guarded via validateCanEdit, cross-workspace NotFound defense-in-depth.
- TemporaryNoteCleanupService: hourly @Interval sweep that soft-deletes expired
  notes through the exact PageRepo.removePage path (recursive over children,
  emits PAGE_SOFT_DELETED), attributed to the creator; idempotent via
  deletedAt IS NULL filters.
- restorePage clears temporary_expires_at so a restored note can't be re-trashed.
- Workspace setting temporary_note_hours (audit-tracked) + a hours editor in
  workspace General settings.
- Client: second create button, orange tree icon, tree + page-header menu toggle
  ("Make temporary"/"Make permanent"), an open-note banner with a rescue action,
  and en/ru i18n.

Tests (unit): toggle-temporary controller (toggle/explicit/permission/cross-ws +
DTO validation), cleanup-job sweep (selection filters, per-note removePage,
error isolation), and a migration up/down sanity. Server tsc, client tsc -b,
and the page+workspace jest suites are green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/server/src/core/workspace/dto/update-workspace.dto.ts

@@ -84,6 +84,13 @@ export class UpdateWorkspaceDto extends PartialType(CreateWorkspaceDto) {
   @Min(1)
   trashRetentionDays: number;
 
+  // Default lifetime for new temporary notes, in HOURS. Frozen per-note at
+  // creation, so changing this never reschedules existing notes.
+  @IsOptional()
+  @IsInt()
+  @Min(1)
+  temporaryNoteHours: number;
+
   @IsOptional()
   @IsBoolean()
   allowMemberTemplates: boolean;

apps/server/src/core/workspace/services/workspace.service.ts

@@ -330,6 +330,7 @@ export class WorkspaceService {
     if (
       typeof updateWorkspaceDto.disablePublicSharing !== 'undefined' ||
       typeof updateWorkspaceDto.trashRetentionDays !== 'undefined' ||
+      typeof updateWorkspaceDto.temporaryNoteHours !== 'undefined' ||
       typeof updateWorkspaceDto.mcpEnabled !== 'undefined' ||
       typeof updateWorkspaceDto.restrictApiToAdmins !== 'undefined' ||
       typeof updateWorkspaceDto.allowMemberTemplates !== 'undefined' ||
@@ -337,7 +338,13 @@ export class WorkspaceService {
     ) {
       const ws = await this.db
         .selectFrom('workspaces')
-        .select(['id', 'licenseKey', 'plan', 'trashRetentionDays'])
+        .select([
+          'id',
+          'licenseKey',
+          'plan',
+          'trashRetentionDays',
+          'temporaryNoteHours',
+        ])
         .where('id', '=', workspaceId)
         .executeTakeFirst();
 
@@ -378,6 +385,14 @@ export class WorkspaceService {
         before.trashRetentionDays = ws.trashRetentionDays;
         after.trashRetentionDays = updateWorkspaceDto.trashRetentionDays;
       }
+
+      if (
+        typeof updateWorkspaceDto.temporaryNoteHours !== 'undefined' &&
+        updateWorkspaceDto.temporaryNoteHours !== ws.temporaryNoteHours
+      ) {
+        before.temporaryNoteHours = ws.temporaryNoteHours;
+        after.temporaryNoteHours = updateWorkspaceDto.temporaryNoteHours;
+      }
     }
 
     if (updateWorkspaceDto.aiSearch) {