Add files components 406-420; Tree opens to a known choice

Fifteen file components: FileExplorer, FileGrid, FileIcon, PathBar,
MemoryCard, DiskUsage, UploadQueue, Trash, RecentFiles, FilePreview,
ArchiveViewer, FileDetails, SharePanel, SyncStatus and QuotaMeter.

FileIcon draws six kinds as hand-placed 12x12 pages and a folder. The
browsers build on data.Tree, List, GridView and Table; ArchiveViewer
owns its sort and keeps the caller's index on its entry. UploadQueue
keys rows by name so focus stays on its row. SharePanel never logs the
link. SyncStatus turns its arrows on Busy steps, so syncing moves under
Reduce Motion.

data.Tree now opens the closed branches above a chosen path it knows,
so a caller's starting path survives the first frame.

files/recentfiles.go

@@ -0,0 +1,48 @@
+package files
+
+import (
+	"fmt"
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/data"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/datetime"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type RecentFilesOptions struct {
+	// Width and Height are dots; zeros mean 220, 120.
+	Width, Height int
+	Disabled      bool
+}
+
+type RecentFilesResult struct {
+	Element *ui.Element
+	// Opened is Enter or a double click on a file.
+	Changed, Opened bool
+}
+
+// RecentFiles lists files with how long since each changed.
+func RecentFiles(c *ui.Context, text string, files []File, selected *int, o RecentFilesOptions) RecentFilesResult {
+	k := pixel.K(c)
+	pick("RecentFiles", selected, len(files))
+	for _, f := range files {
+		check("RecentFiles", f)
+		if f.Modified.IsZero() {
+			panic(fmt.Sprintf("files: RecentFiles %q has no time", f.Name))
+		}
+	}
+	var res RecentFilesResult
+	res.Element = ui.Column(c).Width(k.D(pixel.Or("RecentFiles Width", o.Width, 220))).Children(func() {
+		l := data.List(c, text, len(files), selected, data.ListOptions{Height: o.Height, Disabled: o.Disabled}, func(i int) string { return files[i].Name }, func(i int) {
+			row(c, k, files[i], func() { datetime.RelativeTime(c, files[i].Modified, datetime.RelativeTimeOptions{}) })
+		})
+		l.Element.FillWidth()
+		res.Changed, res.Opened = l.Changed, l.Submitted && *selected >= 0
+	})
+	if res.Opened {
+		slog.Debug("8bit: recent files open", "label", text, "file", *selected)
+	}
+	return res
+}