* Add admin users management page with pagination, search, and inline username editing
https://claude.ai/code/session_01E4UUQqQedhFP2F5YcBRArs
* Fix five issues from admin users page code review
- admin.users: use useEffect to close inline edit on success so validation
errors are not silently discarded when the save button fires onClick
- root: add /admin to ONBOARDING_EXEMPT so admin users without a username
are not redirect-looped away from admin pages
- settings: skip username validation when the username field is empty so
updating timezone alone does not break for accounts without a username
- models/user: exclude soft-deleted users from findUsersPaginated
- admin.users: remove unused hasMore from loader return; simplify header div
https://claude.ai/code/session_01E4UUQqQedhFP2F5YcBRArs
* Fix lint: rename shadowed variables in user model
- findUserByUsername: use imported sql directly instead of destructuring
it from the callback (shadowed the top-level import)
- findUsersPaginated: rename orderBy callback param from users to t
(shadowed the outer users result variable)
https://claude.ai/code/session_01E4UUQqQedhFP2F5YcBRArs
---------
Co-authored-by: Claude <noreply@anthropic.com>