Files · Explorer: a folder as a list, tiles or columns, with one path and one order

FileExplorer shows the folder at the end of a path three ways: the
directory listing, a grid of tiles, or a column per folder along the
path with the next folder lit. Its name, its count and a switch of views
sit above one path bar that climbs. A folder opens in place; a file goes
to the host, which lists each folder it goes to. A pick in an earlier
column closes the columns past it, and a new deepest column scrolls into
view. The directory listing takes its pick from its owner and reports
it, so the pick carries across views; its path bar and its first order
are shared. The gallery walks a small file system and shows the tree,
the context menu, renaming in place and a drop zone in use.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tasks/ch21-30.md

@@ -296,12 +296,12 @@
 
 ## T27b Files · Explorer
 
-- [ ] FileExplorer — list, icons, columns
-- [ ] FileBreadcrumb / PathBar → `navigation::Breadcrumb`
-- [ ] FolderTree → `lists::FileTree`
-- [ ] FileContextMenu → `menus::ContextMenu`
-- [ ] RenameInline → `forms::InlineEdit`
-- [ ] DragDropFiles → `forms::DropZone`
+- [x] FileExplorer — list, icons, columns
+- [x] FileBreadcrumb / PathBar → `navigation::Breadcrumb`
+- [x] FolderTree → `lists::FileTree`
+- [x] FileContextMenu → `menus::ContextMenu`
+- [x] RenameInline → `forms::InlineEdit`
+- [x] DragDropFiles → `forms::DropZone`
 
 ## T27c Files · Find and look