API: new updateName adminProcedure in user router
- Input: userId + name (min 1, max 200 chars)
- Argon2 not involved (name only, not password)
- Audit log: "Changed name from X to Y"
UI: "Display Name" editable section in user edit modal
- Shows current name with "Edit" link
- Click Edit: inline input with Save/Cancel + Enter/Escape
- Auto-focuses input, saves on Enter
- Invalidates user list on success
Co-Authored-By: claude-flow <ruv@ruv.net>