This commit introduces the capability to edit existing items. The `ItemEditModal` has been refactored to support both creation and editing modes.
- The modal UI (title, buttons) and submission logic now adapt based on whether an item is being added or edited.
- A new `editItem` function is added to the `useItemsStore` to handle the update logic.
- Form validation for the item name is enhanced to correctly check for uniqueness during edits.
- The table's row action menu now opens the modal in edit mode, pre-populating the form.
- The `latestId` generation logic is improved for robustness.
- Additionally, this commit adds row selection checkboxes to the items table.
This commit introduces the ability to delete items. A new `ItemDeleteModal` component provides a confirmation step
before removal.
- Adds a 'Delete' option to the action menu in the items table.
- Refactors the `useItems` composable to ensure reactivity with `useLocalStorage` by creating new array references on
add/remove operations.
- Renames `AddModal` to `EditModal` to better align with its future role in both adding and editing items.
