Show success/failure messages for bookmark create/update/remove actions

## Context

Several bookmark UI actions currently only `console.debug`/`console.error` on success/failure instead of surfacing feedback to the user:

- `packages/react/components/bookmark/src/components/create-bookmark/CreateBookmark.tsx` — after creating a bookmark
- `packages/react/components/bookmark/src/components/edit-bookmark/EditBookmark.tsx` — after updating a bookmark
- `packages/react/components/bookmark/src/components/sectionList/SectionList.tsx` — after "Update with current view" and "Remove" actions

## Task

Add a user-visible success/failure message (e.g. a toast/snackbar) for bookmark create, update, and remove actions in the components listed above.

## Acceptance criteria

- [ ] Creating a bookmark shows a success or failure message
- [ ] Updating a bookmark (including "update with current view") shows a success or failure message
- [ ] Removing a bookmark shows a success or failure message

Start by reading CreateBookmark.tsx, EditBookmark.tsx, and SectionList.tsx, tracing the create, update, update-with-current-view, and remove action handlers. Identify the project's user-visible feedback pattern, then verify that each listed action shows success or failure feedback and that the existing bookmark behavior remains intact.

Written by the indexing model from the issue text.