## User Story:
Similar to the watchlist expiry time, it should be possible for a user to set the watchlist labels for a page after they've clicked the watchstar (or watch link, on skins without a star).
## Details:
* Add a new menu chevron next to the watchstar* When selecting the Watch star, a popup opens, with which to open the popup that shows the edisplaying Expiry and lLabels fields and an 'unwatch' button.
* The menu arrow should only be visible if either $wgWatchlistExpiry or $wgEnableWatchlistLabels is trueis popover replaces the previous mw.notify notification.
* The labels field is a MenuMultiselectLookup widget, with which it is possible to autocomplete on any of a user's watchlist labels. The labels are available from the `action=userinfo` API, and should not be loaded at page load time (note that the modules for the notification and popup are also not loaded, so they and the data can be loaded at the same time)popover times out by itself after 5 seconds if not interacted with.
* The exis* When selecting notification will be simplified to just the confirmation messagethe Watch star, the page is immediately watched or unwatched, and an 'Organise' button that opens the watchstarregardless of whether the user interacts with the popupover.
* Clicking the watchstar will only watch or unwatch;The labels field is a MenuMultiselectLookup widget, with which it is possible to autocomplete on any of a user's watchlist labels. The labels are available from the `action=userinfo` API, to geand should not be loaded at page load time (note that the other optionse modules for the notification and popup are also not loaded, the dropdown arrow will need to be clickedso they and the data can be loaded at the same time).
* There will be a hyperlink from the watch popup to Special:WatchlistLabels.
* Any number of labels will be able to be selected. As each is selected (i.e. its InfoChip appears) the set of labels is saved. This avoids the need for a 'save' button, and follows the behaviour of the expiry dropdown.
* No new labels are able to be created from this place.
* The `action=watch` API is updated to accept label IDs for assigning. T416291.
* The `action=watch` page action is updated to show a new 'watchlist labels' field. T418547
* When the Watch/Unwatch is in the tools menu as a link (e.g. $wgVectorUseIconWatch=false) then the popup won't be available. (Details t.b.a.)
## Details for QA:
* Should work in all supported skins.
* No-JS flow should make sense and all features be usable.
* Clicking the watchstar or menu triggers the loading of some extra ResourceLoader modules, and on slow connections this can be a noticeable delay. Some skins (e.g. Vector) indicate this by spinning the star.
## Designs:
https://www.figma.com/design/CdyroPkkcT7GJA9bwno0Rq/WE1.4-Task-priotization?node-id=429-133223&t=OZMuLaAu0fF3Nofq-1 re
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