[Due for payment 2026-07-29] fix: task assignee resolution for composer short mentions

[mountiny]

Problem

Creating a task with a short mention ([] @name Task title) has not assigned the task since July 2025. The composer passed bare usernames (name) into addDomainToShortMention, which checks full logins (name@domain.com). This check never matched, so the task was created unassigned with @name left in the title.

Solution

The fix feeds addDomainToShortMention the full logins list via a new getAllPersonalDetailLogins() in PersonalDetailsUtils, and looks up the assignee with the existing getPersonalDetailByEmail. Both reads happen at submit time, so the composer input and send button no longer subscribe to the personal details collection on render.

PR

#96500

Issue Owner

Current Issue Owner: @ZhenjaHorbach