Add overlay components 176-195; pixel Harbor and Kit.Cue

Dialogs on DialogBase with focusable panels that harbor parked focus,
popovers on PopoverBase, bubbles, drawers, sheets, a lightbox, an RPG
dialogue box, notifications, a pause menu and a dithered title card.
Kit.Cue moves from feedback to pixel.

overlay/drawer.go

@@ -0,0 +1,63 @@
+package overlay
+
+import (
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/display"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+type DrawerOptions struct {
+	// Side is the edge it slides from.
+	Side display.Side
+	// Size is its depth in dots; zero means 160.
+	Size int
+	// Disabled makes the content inert.
+	Disabled bool
+}
+
+type DrawerResult struct {
+	Element *ui.Element
+	// Closed is Escape or a click outside.
+	Closed bool
+}
+
+// Drawer slides a panel in from an edge in steps.
+func Drawer(c *ui.Context, text string, open *bool, o DrawerOptions, content func()) DrawerResult {
+	k := pixel.K(c)
+	if o.Side > display.Right {
+		panic("overlay: unknown Drawer Side")
+	}
+	size := pixel.Or("Drawer Size", o.Size, 160)
+	home := ui.Box(c)
+	off := k.D(arriving(c, home, *open) * size / 4)
+	was := *open
+	var res DrawerResult
+	res.Element = ui.DialogBase(c, open, func(back, panel *ui.Element) {
+		dim(k, back, pixel.Back, 8)
+		panel.Absolute().Label(text).Padding(k.D(8)).Focusable().FocusRing(false)
+		switch o.Side {
+		case display.Left:
+			panel.Top(0).Bottom(0).Left(-off).Width(k.D(size))
+		case display.Right:
+			panel.Top(0).Bottom(0).Right(-off).Width(k.D(size))
+		case display.Top:
+			panel.Left(0).Right(0).Top(-off).Height(k.D(size))
+		case display.Bottom:
+			panel.Left(0).Right(0).Bottom(-off).Height(k.D(size))
+		}
+		panel.Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			g.Frame(0, 0, g.W, g.H, pixel.Window, pixel.Face)
+		}).Children(func() {
+			pixel.Harbor(c, panel, func() { body(c, o.Disabled, content) })
+		})
+	})
+	res.Closed = was && !*open
+	if res.Closed {
+		slog.Debug("8bit: drawer closed", "label", text)
+	}
+	return res
+}