listAssignablePrincipals

Server-side searchable, paginated list of the USERS and TEAMS that can be assigned as the owner of an improvement or task in a project, and the canonical source for resolving a person's user_id when @-mentioning them in a document. Users are the people who may be assigned work in the project: active members of its organisation who can open the project (organisation owners and admins, the workspace's owner and members, and people with a direct or team share on the project or its workspace, unless a share denies them). Teams are the project's organisation's teams, listed for a caller who is an active member of it. Returns two arrays: users (with user_id, display_name, email, avatar_url, has_explicit_permission for a direct share on the project) and teams (with team_id, name, member_count, has_explicit_permission for a share on the project). Use BEFORE: (1) updateImprovement/updateTask when you need an owner_id (kind='user') or owner_team_id (kind='team'); (2) inserting a <!-- REFERENCE: {"type":"user","id":"…","label":"…"} --> mention in document content via createDocument / editDocument / findAndReplaceTextInDocument. Supports query for a case-insensitive search on names and emails (users) or team names (teams). Pass kind='user' or kind='team' to scope to a single section, or 'all' (default) for both. Pagination via limit (1-100, default 20) and offset.