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/coachmark.go

@@ -0,0 +1,47 @@
+package overlay
+
+import (
+	"fmt"
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/input"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/text"
+)
+
+type CoachmarkOptions struct {
+	Disabled bool
+}
+
+type CoachmarkResult struct {
+	Element *ui.Element
+	Next    bool
+}
+
+// coachWidth is the bubble's text width in dots.
+const coachWidth = 140
+
+// Coachmark points a bubble at target: step count, NEXT ▶.
+func Coachmark(c *ui.Context, target *ui.Element, message string, step, steps int, o CoachmarkOptions) CoachmarkResult {
+	k := pixel.K(c)
+	if step < 1 || step > steps {
+		panic(fmt.Sprintf("overlay: Coachmark step %d of %d", step, steps))
+	}
+	var res CoachmarkResult
+	res.Element = bubble(c, target.Bounds(), func() {
+		ui.Column(c).Width(k.D(coachWidth)).Gap(k.D(4)).Role(ui.RoleGroup).Label(message).Children(func() {
+			text.Paragraph(c, message, text.ParagraphOptions{})
+			ui.Row(c).AlignItems(ui.Center).Children(func() {
+				text.MicroText(c, fmt.Sprintf("%d/%d", step, steps), text.MicroTextOptions{Slot: pixel.Faint})
+				ui.Box(c).Grow(1)
+				res.Next = input.Button(c, k.Msg("next_step"), input.ButtonOptions{Size: input.Small, Variant: input.Primary, Disabled: o.Disabled}).Clicked
+			})
+		})
+	}, coachWidth+16)
+	if res.Next {
+		slog.Debug("8bit: coachmark next", "step", step, "steps", steps)
+	}
+	return res
+}