Sidebar-section-styled panel (p-4 card, mobile <details> accordion, no
inner scroll clamp) that lists a story's journey items in position order.
Add is pessimistic via POST /items; remove is optimistic with snapshot
rollback via DELETE /items/{id}; both through csrfFetch. Already-linked
documents are unselectable in the reused DocumentPickerDropdown (visible
label wired via inputId). Document-less items (ON DELETE SET NULL)
render as removable placeholder rows. 409 capacity/duplicate map to
story-worded messages, everything else through getErrorMessage(). Add/
remove are announced in a polite live region and focus moves to the
previous row's remove button (picker input when the list empties).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
