Skill credentials follow the DSH session owner, so a chat created under
the emergency account stays owned by administrator after a QR scan and
skills cannot get a UAC token there. The generic "scan QR first" error
hid this.
- Return session_owner_no_uac when the owner is administrator / a local
account, telling the user to start a new session after QR sign-in.
- Name the owner in no_skill_credentials for UAC owners.
- Audit denied outbound calls with session id and owner.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
