Search results when adding a member to a project are limited to 10

[jkbmdk]

Is your feature request related to a problem? Please describe.
When assigning users/groups to a project, the "add member" / "add group" search dropdowns only ever fetched the first page (10 results) of matches. If a search term matched more than 10 users or groups, the remaining ones were unreachable in the UI.

Screen.Recording.2026-08-07.at.12.27.12.mov

Describe the solution you'd like
Adding an infinite-scroll pagination to both dropdowns (add-member and add-group components)

Describe the main design/architecture of your solution

• Switching from searchUsers / searchUserGroups (body-only) to searchUsersResponse / searchUserGroupsResponse, which expose response headers so X-Total-Count can be read.
• Adding pagination state (page, pageSize, totalCount, current search name) and a loadNextPage() method that fetches the next page and appends results, guarded against concurrent/duplicate loads and fetching past the total count.
• Wiring a (scroll) handler on the dropdown container that triggers loading the next page when the user scrolls near the bottom.
• Updating the SCSS to give the dropdown a fixed max-height with overflow-y: auto (previously height: auto, so scrolling wasn't even possible), plus a small spinner shown while loading more results.

Describe the development plan you've considered
I already prepared and tested the solution. I would also like to request that this solution be backported to version 2.14 and 2.15

Additional context
Here is a short video showing the solution, compared to network traffic. Notice that next are loaded when scroll goes to the bottom.

Screen.Recording.2026-08-07.at.12.43.25.mov

[Vad1mo]

What if you type in test1, you chuld get test1,test11, test12... etc.
I know it's not perfect, but it is also not a dealbreaker, since workarounds exist.

Extending the current implementation into a full-blown search is more effort and a potential breaking change.

[jkbmdk]

Thanks @Vad1mo for the feedback. It seems the example I posted doesn't quite capture the essence of the problem, as it's a case where groups are ranked, and we're searching for them by entering the beginning of their names. It's much more difficult to do this when we only know the last part of the group name.

I agree that search can be achieved without that change, but I took the liberty of starting a PR so that we could assess how this change affects the codebase.