Add agent components 451-465 and icon.Crystal

Fifteen components that dress an AI agent's work as an RPG party:
AgentCard, ToolCall, PlanQuest, ThinkingOrb, TokenMana, ApprovalPrompt,
AgentLog, SubAgentParty, MemoryCrystals, AgentStatus, DiffScroll,
ModelSelect, PromptBox, CostCoins and Checkpoints.

The context window is HP and the token budget MP; tool calls are spells
that CAST, glow, then land OK or FAILED; the transcript reads as a battle
log whose newest line types itself out; models line up like fighters.
Busy signs keep moving under Reduce Motion, decoration stops. Commands
and prompts never reach the log, and a veiled PromptBox casts nothing.

icon.Crystal is the new 12x12 save and memory crystal.

agent/modelselect.go

@@ -0,0 +1,125 @@
+package agent
+
+import (
+	"fmt"
+	"log/slog"
+
+	"github.com/egoist/mygo/ui"
+
+	"git.zacharyzhang.com/ZacharyZhang-NY/8bitMyGoUI/pixel"
+)
+
+// Model is a fighter to pick; stats run 1–5.
+type Model struct {
+	Name string
+	// Portrait fits 12 dots square; zero means a robot.
+	Portrait           *pixel.Sprite
+	Speed, Power, Cost int
+}
+
+type ModelSelectOptions struct {
+	Disabled bool
+}
+
+type ModelSelectResult struct {
+	Element *ui.Element
+	Changed bool
+}
+
+type pickKey struct{}
+
+const fighter = 30
+
+// ModelSelect picks a model the way fighters are picked.
+func ModelSelect(c *ui.Context, text string, models []Model, chosen *int, o ModelSelectOptions) ModelSelectResult {
+	k := pixel.K(c)
+	if len(models) == 0 || *chosen < 0 || *chosen >= len(models) {
+		panic(fmt.Sprintf("agent: ModelSelect chose %d of %d", *chosen, len(models)))
+	}
+	faces := make([]*pixel.Sprite, len(models))
+	for i, m := range models {
+		for _, s := range []int{m.Speed, m.Power, m.Cost} {
+			if m.Name == "" || s < 1 || s > 5 {
+				panic(fmt.Sprintf("agent: ModelSelect model %q has a stat of %d", m.Name, s))
+			}
+		}
+		faces[i] = portrait("ModelSelect", m.Portrait)
+	}
+	cols, old := min(len(models), 4), *chosen
+	row := ui.Row(c).Gap(k.D(8)).AlignItems(ui.Start)
+	cur := ui.Local(row, pickKey{}, func() int { return *chosen })
+	*cur = min(*cur, len(models)-1)
+	res := ModelSelectResult{}
+	res.Element = row.Children(func() {
+		shell, base, st, picked := pixel.Pad(c, text, cols, len(models), fighter, fighter, cur, o.Disabled)
+		if picked >= 0 {
+			*chosen = picked
+		}
+		at, pick := *cur, *chosen
+		m := models[at]
+		stats := []struct {
+			name  string
+			value int
+			ink   pixel.Slot
+		}{{k.Msg("speed"), m.Speed, pixel.Info}, {k.Msg("power"), m.Power, pixel.Bad}, {k.Msg("cost"), m.Cost, pixel.Warn}}
+		said := m.Name
+		for _, s := range stats {
+			said += fmt.Sprintf(", %s %d", s.name, s.value)
+		}
+		if at == pick {
+			said += ", " + k.Msg("chosen")
+		}
+		base.Description(said)
+		shell.Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			for i, f := range faces {
+				x, y := i%cols*fighter, i/cols*fighter
+				// The cursor lights its cell; the portrait shows on it.
+				if i == at && st.Focus {
+					g.Cursor(x, y, fighter, fighter)
+				} else {
+					g.Frame(x+1, y+1, 28, 28, pixel.Sunken, pixel.Well)
+				}
+				g.Sprite(x+15-f.W, y+15-f.H, f, 0, pixel.Ink, 2)
+				// The chosen fighter wears an Accent ring and corner.
+				if i == pick {
+					g.Rect(x+1, y+1, 28, 1, pixel.Accent)
+					g.Rect(x+1, y+28, 28, 1, pixel.Accent)
+					g.Rect(x+1, y+1, 1, 28, pixel.Accent)
+					g.Rect(x+28, y+1, 1, 28, pixel.Accent)
+					g.Rect(x+2, y+2, 6, 2, pixel.Accent)
+					g.Rect(x+2, y+4, 4, 2, pixel.Accent)
+					g.Rect(x+2, y+6, 2, 2, pixel.Accent)
+				}
+			}
+			g.Finish(st)
+		})
+		// The panel shows the fighter under the cursor, bobbing.
+		face := faces[at]
+		ui.Box(c).Size(k.D(120), k.D(98)).Role(ui.RoleNone).Draw(func(p *ui.Painter, r ui.Rect) {
+			g := k.Canvas(p, r)
+			g.Frame(0, 0, g.W, g.H, pixel.Double, pixel.Face)
+			g.Sprite(6+3*(12-face.W)/2, 6-g.Step(4)%2+3*(12-face.H)/2, face, 0, pixel.Ink, 3)
+			g.Text(48, 6, pixel.Wrap(m.Name, g.W-52, 1)[0], pixel.Ink, 1)
+			if at == pick {
+				g.Text(48, 22, pixel.Wrap(k.Msg("chosen"), g.W-52, 1)[0], pixel.Good, 1)
+			}
+			for i, s := range stats {
+				y := 46 + i*pixel.LineHeight
+				g.Text(6, y, pixel.Wrap(s.name, 40, 1)[0], pixel.Faint, 1)
+				for j := range 5 {
+					ink := pixel.Shade
+					if j < s.value {
+						ink = s.ink
+					}
+					g.Rect(50+j*12, y+5, 10, 6, ink)
+				}
+			}
+		})
+	})
+	res.Changed = *chosen != old
+	if res.Changed {
+		slog.Debug("8bit: model chosen", "label", text, "model", models[*chosen].Name)
+	}
+	return res
+}