The native trash bin is removed from the sheet form, list and kanban views.
Sheets are deleted from the **Delete Sheet** button in the header of the sheet
form, or from the **Action** menu of the list view for several sheets at once.

Both open a confirmation wizard that lists the sheets, the number of timesheet
entries and the total number of hours that will be deleted, and a time off
section that depends on the configured policy. Nothing is deleted until
**Delete permanently** is pressed, and the button is hidden when something
blocks the deletion.

A plain ``sheet.unlink()`` from a script or a server action raises a
``UserError`` that points to the button, so the confirmation step cannot be
skipped by accident. Code that really means to delete does
``sheet._with_delete_cascade().unlink()``.

The cascade is armed by a sentinel object rather than by a plain value in the
context, and ``_with_delete_cascade()`` is the only way to obtain it. The
context of an RPC call is controlled by the caller, so a context flag holding
a JSON value could be forged by any authenticated user and would delete a
sheet without ever showing the confirmation; a sentinel compared by identity
cannot be produced by a deserializer, and a method whose name starts with an
underscore cannot be reached remotely.

With the ``Cancel the time off`` policy, cancelling a time off request posts a
message in its chatter telling the employee that the request has been refused.
The wording talks about a refusal, not about a deleted timesheet sheet.