Add the built-in _desktop plugin as the owner of Xpra/Xfce lifecycle, /desktop route installation, Desktop state, session APIs, surface registration, and the linux-desktop skill. Leave _office with explicit compatibility facades and self-update delegates so users coming from 1.10 through 1.13 keep their runtime cleanup path.
Make the Office canvas mount passive so Xpra starts only when the Desktop surface is opened or an official Office document is created/opened.
Track Desktop host visibility to unload hidden frames, stop monitors, dedupe viewport resize work, and set Xpra offscreen mode according to HTTPS support. Add a near-future note for the tunnel memory footprint.
Show Office desktop startup progress
Display a loading message while the Agent Zero Desktop environment is starting or restarting, so the right-canvas Desktop button gives immediate feedback before Xpra finishes waking up.
Remove the Collabora/WOPI runtime and route stack, including the old status APIs, proxy helpers, bootstrap extensions, and WOPI store tests. Add the Markdown-first document store, LibreOffice status/conversion helpers, LibreOfficeKit session bridge, and reusable Xpra virtual desktop gateway used by the new document runtime.
Update image and self-update bootstrap paths so existing containers can acquire the LibreOffice, XFCE, Xpra, and desktop-control dependencies through the normal install hooks instead of an ad hoc manual install.
