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.md

@@ -94,7 +94,7 @@ Per-component lines live in `tasks/`. Tags there:
 - [x] T26c Media · Video
 - [x] T26d Media · Audio and controls
 - [x] T26e Media · Capture and devices
-- [ ] T27a Files · Items
+- [x] T27a Files · Items
 - [ ] T27b Files · Explorer
 - [ ] T27c Files · Find and look
 - [ ] T27d Files · Transfers
@@ -322,3 +322,4 @@ Per-component lines live in `tasks/`. Tags there:
 | T26e | 1 | FAIL | an option list had no width limit, so a long device name ran it past the window |
 | T26e | 2 | PASS | |
 | T27a | 1 | FAIL | a tile's long name leaned on gpui's line_clamp, which cut its second line at both ends and lost the extension |
+| T27a | 2 | PASS | |