Add a new settings page under Settings > Sessions that shows all active
and expired login sessions with user info, IP address, device, and an
option to revoke (force logout) any session.
Backend:
- listSessions: adminProcedure that returns sessions joined with user
data, ordered by creation date
- revokeSession: adminProcedure that deletes a session by ID (blocks
self-revocation)
Frontend:
- New /dashboard/settings/sessions page with ShowSessions component
- Sessions table with user, IP, device, timestamps, and revoke action
- Sidebar link under Users (gated by member.read permission)
Tests:
- Input validation tests for revokeSession schema