Add account components 386-405; Reduce setting, PinInput Cmd+V

Twenty account components: SettingsList, OptionCycler, KeyBindings,
ControllerMap, ProfileCard, CharacterCreator, LoginForm, PasswordGrid,
SessionList, LanguagePicker, PalettePicker, VolumeMixer,
DifficultySelect, AccessibilityOptions, AccountSwitcher, PlayerSelect,
TwoFactor, About, PatchNotes and FeedbackForm.

The components never check credentials, and no secret reaches the log:
LoginForm reports Submitted and the caller counts Failures; each new
failure clears the password, refocuses it, shakes the form and names no
field. TwoFactor builds on input.PinInput and drains an epoch-aligned
period bar. PalettePicker draws each tile in its own palette on a
pixel.Pad grid.

pixel.Settings.Reduce stills motion like the system preference, the
micro font gains '?', display.Face draws avatar faces anywhere, and
input.PinInput pastes on Cmd+V as native hosts send it.

account/passwordgrid.go

@@ -0,0 +1,92 @@
+package account
+
+import (
+	"fmt"
+	"log/slog"
+	"strings"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/input"
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// symbols are what an old cartridge password is spelled with.
+const symbols = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!?-."
+
+type PasswordGridOptions struct {
+	// Length is the password's symbols, 4–24; zero means 12.
+	Length   int
+	Disabled bool
+}
+
+type PasswordGridResult struct {
+	Element *ui.Element
+	// Submitted is END on a full password.
+	Changed, Submitted bool
+}
+
+type gridKey struct{}
+
+// PasswordGrid spells *password by picking symbols from a grid.
+func PasswordGrid(c *ui.Context, text string, password *string, o PasswordGridOptions) PasswordGridResult {
+	k := pixel.K(c)
+	n := pixel.Or("PasswordGrid Length", o.Length, 12)
+	if n < 4 || n > 24 || len(*password) > n || strings.Trim(*password, symbols) != "" {
+		panic(fmt.Sprintf("account: PasswordGrid of %d symbols holds %d bad or extra", n, len(*password)))
+	}
+	old := *password
+	var res PasswordGridResult
+	res.Element = ui.Column(c).Gap(k.D(5)).Role(ui.RoleGroup).Label(text)
+	cur := ui.Local(res.Element, gridKey{}, func() int { return 0 })
+	res.Element.Children(func() {
+		typed := *password
+		ui.Box(c).Size(k.D(n*9+(n-1)/4*4), k.D(13)).Role(ui.RoleText).Label(fmt.Sprintf("%s %d/%d", text, len(typed), n)).Description(typed).Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			// Blanks in fours, as the old screens printed them.
+			for i := range n {
+				x, line := i*9+i/4*4, pixel.Faint
+				if i < len(typed) {
+					g.Micro(x+2, 4, typed[i:i+1], pixel.Ink, 1)
+				}
+				if i == len(typed) {
+					line = pixel.Accent
+				}
+				g.HLine(x+1, 11, 6, line)
+			}
+		})
+		shell, base, st, picked := pixel.Pad(c, k.Msg("symbols"), 8, len(symbols), 11, 11, cur, o.Disabled)
+		if picked >= 0 && len(*password) < n {
+			*password += symbols[picked : picked+1]
+		}
+		if !base.IsDisabled() && base.Shortcut(0, ui.KeyBackspace) && *password != "" {
+			*password = (*password)[:len(*password)-1]
+		}
+		base.Description(symbols[*cur : *cur+1])
+		at := *cur
+		shell.Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			for i := range len(symbols) {
+				x, y, ink := i%8*11, i/8*11, pixel.Ink
+				if i == at {
+					g.Rect(x, y, 11, 11, pixel.Accent)
+					ink = pixel.AccentInk
+				}
+				g.Micro(x+4, y+3, symbols[i:i+1], ink, 1)
+			}
+			g.Finish(st)
+		})
+		ui.Row(c).Gap(k.D(4)).Children(func() {
+			if input.Button(c, k.Msg("back"), input.ButtonOptions{Size: input.Small, Disabled: o.Disabled || *password == ""}).Clicked {
+				*password = (*password)[:len(*password)-1]
+			}
+			res.Submitted = input.Button(c, k.Msg("end"), input.ButtonOptions{Size: input.Small, Variant: input.Primary, Disabled: o.Disabled || len(*password) < n}).Clicked
+		})
+	})
+	res.Changed = *password != old
+	// Lengths only: the password stays off the log.
+	if res.Changed || res.Submitted {
+		slog.Debug("8bit: password grid", "label", text, "length", len(*password), "submitted", res.Submitted)
+	}
+	return res
+}