Keep _office focused on document artifacts, Markdown sessions, LibreOffice-compatible file actions, and document persistence. Route binary document editing through explicit Desktop requests instead of cold-opening the live Desktop surface from artifact results.
Rework the Office canvas into the Desktop surface, with Markdown editing for text documents and official LibreOffice/Xpra sessions for DOCX, XLSX, and PPTX. The panel now presents Desktop-oriented actions, named header buttons, persistent session tabs, adaptive modal/canvas sizing, and fast client-side Xpra frame fitting during resize.
Stop auto-opening the canvas from document tool results, hide the canvas on mobile-width layouts, and emit resize lifecycle events so embedded desktop surfaces can pause expensive work while the user drags.
