Open filetree mindmap assets inside the primary document pane so the sidebar root is not rebuilt during rapid mindmap/page switching.
Keep filetree active rows on doc:<documentId> and asset:<mindmapId>, shorten generated mindmap filenames, and preserve legacy index rows only as compatibility input.
Add task438-task445 browser smokes and close the 4-27/4-38/4-39/4-40 tree-domain bug records.
