Add the avatar vocabulary to UINode (UI capability platform)

Why: plugins and the host need one shared avatar primitive for member/
owner displays in cards, messages, and admin surfaces (user decision
2026-09-30: avatars, cards, settings become base capabilities plugins
reuse directly).

Evidence: go test green with regenerated golden (single avatar with
sub/tone plus a stacked group); omitempty keeps existing wire samples
byte-stable.

Impact: additive optional UINode field + type; unknown-type consumers
ignore it (forward compat). Renderers gain 'avatar' via the ui repo.

Refs: Agent-System-Documents proposal 2026-09-30-ui-redesign-and-auth.md

conformance_test.go

@@ -125,6 +125,12 @@ func TestGoldenCardEvents(t *testing.T) {
 }
 
 func TestGoldenUIVocabularies(t *testing.T) {
+	golden(t, "ui_avatar", []UINode{
+		{Type: UIAvatar, Avatar: &UIAvatarSpec{Name: "weichen", Sub: "OWNER"}},
+		{Type: UIAvatar, Avatar: &UIAvatarSpec{
+			Stack: []UIAvatarSpec{{Name: "甲", Tone: "ok"}, {Name: "乙", Tone: "warn"}, {Name: "丙"}},
+		}},
+	})
 	golden(t, "ui_vocabularies", []UINode{
 		{Type: UIProgress, Progress: &UIProgressSpec{Label: "市场可行性 78%", Value: 0.78, Tone: "ok"}},
 		{Type: UICompare, Compare: &UICompareSpec{

testdata/golden/ui_avatar.json

@@ -0,0 +1,27 @@
+[
+  {
+    "type": "avatar",
+    "avatar": {
+      "name": "weichen",
+      "sub": "OWNER"
+    }
+  },
+  {
+    "type": "avatar",
+    "avatar": {
+      "stack": [
+        {
+          "name": "甲",
+          "tone": "ok"
+        },
+        {
+          "name": "乙",
+          "tone": "warn"
+        },
+        {
+          "name": "丙"
+        }
+      ]
+    }
+  }
+]

ts/types.ts

@@ -152,7 +152,7 @@ export interface HITLResponse {
 
 export type UINodeType =
   | 'section' | 'list' | 'kv' | 'form' | 'markdown' | 'doc-ref' | 'actions' | 'chart-lite'
-  | 'progress' | 'compare' | 'tree' | 'table' | 'steps' | 'tabs' | 'timeline';
+  | 'avatar' | 'progress' | 'compare' | 'tree' | 'table' | 'steps' | 'tabs' | 'timeline';
 
 export interface UINode {
   type: UINodeType;
@@ -166,6 +166,7 @@ export interface UINode {
   chart?: { kind: 'bar' | 'line'; labels: string[]; series: number[] };
   children?: UINode[];
 
+  avatar?: { name?: string; sub?: string; tone?: string; stack?: { name?: string; sub?: string; tone?: string }[] };
   progress?: { label?: string; value: number; tone?: string };
   compare?: {
     left: { title?: string; tone?: string; nodes?: UINode[] };

ui.go

@@ -17,6 +17,7 @@ const (
 	UIChartLite UINodeType = "chart-lite"
 	// —— 收件箱/工作区扩展词汇（提案 D28；graph 远期，追溯视图按"对象为中心 +
 	// 分组泳道 + 逐层展开"约束设计，禁止力导向裸图）——
+	UIAvatar   UINodeType = "avatar"   // 头像（成员/责任人展示；UI 能力平台，插件可用）
 	UIProgress UINodeType = "progress" // 进度条（摄取/生成/填充度）
 	UICompare  UINodeType = "compare"  // 左右对比（基线 vs 新内容、diff 确认）
 	UITree     UINodeType = "tree"     // 树（文档树/笔记树骨架；节点带状态灯/徽标/计数）
@@ -27,24 +28,33 @@ const (
 )
 
 type UINode struct {
-	Type     UINodeType `json:"type"`
-	Title    string     `json:"title,omitempty"`
-	Items    []string   `json:"items,omitempty"`  // list
-	KV       [][2]string `json:"kv,omitempty"`    // kv
-	Fields   []UIField  `json:"fields,omitempty"` // form
-	Markdown string     `json:"markdown,omitempty"`
-	DocID    ID         `json:"docId,omitempty"`  // doc-ref
-	Actions  []UIAction `json:"actions,omitempty"`
-	Chart    *UIChart   `json:"chart,omitempty"`
-	Children []UINode   `json:"children,omitempty"` // section
+	Type     UINodeType  `json:"type"`
+	Title    string      `json:"title,omitempty"`
+	Items    []string    `json:"items,omitempty"`  // list
+	KV       [][2]string `json:"kv,omitempty"`     // kv
+	Fields   []UIField   `json:"fields,omitempty"` // form
+	Markdown string      `json:"markdown,omitempty"`
+	DocID    ID          `json:"docId,omitempty"` // doc-ref
+	Actions  []UIAction  `json:"actions,omitempty"`
+	Chart    *UIChart    `json:"chart,omitempty"`
+	Children []UINode    `json:"children,omitempty"` // section
 
-	Progress *UIProgressSpec  `json:"progress,omitempty"` // progress
-	Compare  *UICompareSpec   `json:"compare,omitempty"`  // compare
-	Tree     *UITreeSpec      `json:"tree,omitempty"`     // tree
-	Table    *UITableSpec     `json:"table,omitempty"`    // table
-	Steps    *UIStepsSpec     `json:"steps,omitempty"`    // steps
-	Tabs     *UITabsSpec      `json:"tabs,omitempty"`     // tabs
-	Timeline *UITimelineSpec  `json:"timeline,omitempty"` // timeline
+	Avatar   *UIAvatarSpec   `json:"avatar,omitempty"`   // avatar
+	Progress *UIProgressSpec `json:"progress,omitempty"` // progress
+	Compare  *UICompareSpec  `json:"compare,omitempty"`  // compare
+	Tree     *UITreeSpec     `json:"tree,omitempty"`     // tree
+	Table    *UITableSpec    `json:"table,omitempty"`    // table
+	Steps    *UIStepsSpec    `json:"steps,omitempty"`    // steps
+	Tabs     *UITabsSpec     `json:"tabs,omitempty"`     // tabs
+	Timeline *UITimelineSpec `json:"timeline,omitempty"` // timeline
+}
+
+// UIAvatar：头像（成员/责任人；Name 取首字，Tone 走语义色；Stack 为叠放组）。
+type UIAvatarSpec struct {
+	Name  string         `json:"name,omitempty"`
+	Sub   string         `json:"sub,omitempty"`   // 名字旁的小注（角色/状态）
+	Tone  string         `json:"tone,omitempty"`  // ok/warn/danger/info/留空=品牌色
+	Stack []UIAvatarSpec `json:"stack,omitempty"` // 叠放头像组（多成员）
 }
 
 // UIProgress：0–1 归一进度或 n/m 计数（Value=Done/Total 任一形式，前端按 <1 判定）。
@@ -88,9 +98,9 @@ type UITableColumn struct {
 }
 
 type UITableRow struct {
-	ID      string     `json:"id,omitempty"`
-	Cells   [][2]string `json:"cells"`              // 与 Columns.Key 对应的有序单元格
-	Actions []UIAction `json:"actions,omitempty"`  // 行级操作（走命令总线）
+	ID      string      `json:"id,omitempty"`
+	Cells   [][2]string `json:"cells"`             // 与 Columns.Key 对应的有序单元格
+	Actions []UIAction  `json:"actions,omitempty"` // 行级操作（走命令总线）
 }
 
 type UITableSpec struct {
@@ -146,7 +156,7 @@ type UIField struct {
 type UIAction struct {
 	ID      string `json:"id"`
 	Label   string `json:"label"`
-	Style   string `json:"style,omitempty"`  // primary | default | danger
+	Style   string `json:"style,omitempty"`   // primary | default | danger
 	Command string `json:"command,omitempty"` // 绑定命令总线命令 id；空则降级为发消息
 }