When on a Poster Session in Pres Mgmt, the Launcher nav link now appends
?iframe=true&launcher_menu=hide so the recipient opens a clean kiosk view
without the site header or left session panel.
- ae_comp__events_menu_nav: add events__launcher_extra_params prop; update
launcher_sess_qry to merge extra params after session_id
- session_page_menu: derive is_poster from type_code and pass the kiosk
params into the Launcher link