Open and close notebooks as remembered state, a first-run screen, the notebook
sidebar behind a notebook-icon rail, New Notebook/Section/Page with OneNote's
menus, the template strip (Ivy, Purple Clouds, Notebook, Solid Color, Meeting)
drawn with our own art, page colours, drag to reorder and to move pages across
sections, and mounted SMB shares opened through the embedded client. Linux uses
the desktop's titlebar (KWin server-side, Adwaita frame on GNOME). Clicks that
change state always get another frame. Conflict highlighting lives in canvas.

Assisted-by: claude-opus-5.5
Assisted-by: claude-opus-5