Add code components 366-385; ScrollArea Follow, editor sync

A terminal with history, a Go-colored code block, a log viewer that
follows, a hex viewer, a memory map, a JSON tree, a line diff, a GAME
OVER crash screen, an FPS meter, profiler bars, breakpoints,
variables, command history, a shortcut list, a debug grid, a pixel
editor that exports string art, a palette editor, a sprite sheet, a
glyph map and a 6502 register view.

layout.ScrollArea takes Follow, and ChatLog now uses it. data.TreeNode
takes a Value drawn in its Slot. pixel gains Has, and Sprite.Art
writes MustSprite art. pixel.Editor takes the caller's value at each
input event, so a value changed between frames is never typed onto.

code/commandhistory.go

@@ -0,0 +1,41 @@
+package code
+
+import (
+	"log/slog"
+	"strconv"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/data"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type CommandHistoryOptions struct {
+	// Width and Height are dots; zeros mean 200 by 120.
+	Width, Height int
+	Disabled      bool
+}
+
+type CommandHistoryResult struct {
+	Element *ui.Element
+	// Rerun is Enter or a double click on a command.
+	Changed, Rerun bool
+}
+
+// CommandHistory numbers past commands; Enter reruns one.
+func CommandHistory(c *ui.Context, text string, commands []string, selected *int, o CommandHistoryOptions) CommandHistoryResult {
+	k := pixel.K(c)
+	var r data.ListResult
+	e := ui.Box(c).Width(k.D(pixel.Or("CommandHistory Width", o.Width, 200))).Children(func() {
+		r = data.List(c, text, len(commands), selected, data.ListOptions{Height: o.Height, Disabled: o.Disabled}, func(i int) string { return commands[i] }, func(i int) {
+			ui.Row(c).Gap(k.D(4)).Children(func() {
+				pixel.Text(c, strconv.Itoa(i+1), pixel.TextOptions{Slot: pixel.Faint})
+				pixel.Text(c, commands[i], pixel.TextOptions{MaxLines: 1})
+			})
+		})
+	})
+	if r.Submitted {
+		slog.Debug("8bit: command history rerun", "label", text, "index", *selected)
+	}
+	return CommandHistoryResult{Element: e, Changed: r.Changed, Rerun: r.Submitted}
+}