apps gain kiosk_path/kiosk_caps (hvac registered first). One shared kiosk
password mints a long-lived hnf_kiosk_session carrying only each registered
app's kiosk caps; /verify answers for kiosk sessions; changing the password
bumps an epoch that invalidates signed-in tablets.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>