Add U1 task summary body contract helpers

Why: Freeze L1 skeleton KV keys and honest no-findings placeholder
so Backend can stop stuffing raw task text into progress cards.
Evidence: go test ./... -count=1
Impact: New TaskSummaryView helpers; findings[] still deferred to U2/U3.
Refs: fast-slow-channel-display-u1-plan W1

Co-authored-by: Cursor <cursoragent@cursor.com>

task_summary.go

@@ -0,0 +1,100 @@
+package core
+
+// TaskSummaryView 是 U1 写入 ActivityCard.Body 的权威语义草图。
+// 完整 TaskSnapshot（findings[]、revision、streamScope）留待 U2；本类型只冻结
+// 运行中/终态的精炼骨架字段与 Body KV 键名，供 Backend 生成、旧客户端回退阅读。
+type TaskSummaryView struct {
+	Title        string // 业务动宾短标题（通常已在 ActivityCard.Title）
+	Focus        string // 正在做什么，≤2 行
+	FindingsNote string // U1：无成果时诚实占位；结构化 findings 属 U3
+	Remaining    string
+	NextStep     string
+	OutcomeLine  string // 完成后的结论一行；运行中可空
+}
+
+// Body KV 键名（U1 冻结；用户默认卡身可见，勿改成内部材料键）。
+const (
+	TaskSummaryKVStatus   = "状态"
+	TaskSummaryKVFocus    = "正在做"
+	TaskSummaryKVFindings = "当前发现"
+	TaskSummaryKVRemaining = "剩余"
+	TaskSummaryKVNextStep = "下一步"
+)
+
+// 状态行用户文案（与执行态映射；排队/进行中/完成/失败）。
+const (
+	TaskSummaryStatusQueued  = "排队中"
+	TaskSummaryStatusRunning = "进行中"
+	TaskSummaryStatusDone    = "已完成"
+	TaskSummaryStatusFailed  = "执行失败"
+)
+
+// 无阶段成果时的诚实占位（R03-a）；不得编造业务发现。
+const TaskSummaryNoFindingsYet = "尚无阶段结论，正在读取材料"
+
+// RunningBody 生成运行中（含排队）进度卡 Body：Markdown 占位 + 固定骨架 KV。
+// extraKV（材料键等）保留在同一 UIKV 节点，供系统去重，不充当用户进度正文。
+func (v TaskSummaryView) RunningBody(statusLabel string, extraKV [][2]string) []UINode {
+	focus := stringsOr(v.Focus, "处理已登记工作")
+	findings := stringsOr(v.FindingsNote, TaskSummaryNoFindingsYet)
+	remaining := stringsOr(v.Remaining, "待任务进展后更新")
+	next := stringsOr(v.NextStep, "继续处理已登记工作")
+	if statusLabel == "" {
+		statusLabel = TaskSummaryStatusRunning
+	}
+	kv := append(append([][2]string(nil), extraKV...),
+		[2]string{TaskSummaryKVStatus, statusLabel},
+		[2]string{TaskSummaryKVFocus, focus},
+		[2]string{TaskSummaryKVFindings, findings},
+		[2]string{TaskSummaryKVRemaining, remaining},
+		[2]string{TaskSummaryKVNextStep, next},
+	)
+	return []UINode{
+		{Type: UIMarkdown, Markdown: findings},
+		{Type: UIKV, KV: kv},
+	}
+}
+
+// FinishedBody 生成终态卡 Body：结论 Markdown + 骨架 KV（状态为已完成或执行失败）。
+func (v TaskSummaryView) FinishedBody(statusLabel string, extraKV [][2]string) []UINode {
+	outcome := stringsOr(v.OutcomeLine, "（无结果摘要）")
+	findings := stringsOr(v.FindingsNote, outcome)
+	if statusLabel == "" {
+		statusLabel = TaskSummaryStatusDone
+	}
+	kv := append(append([][2]string(nil), extraKV...),
+		[2]string{TaskSummaryKVStatus, statusLabel},
+		[2]string{TaskSummaryKVFocus, stringsOr(v.Focus, "")},
+		[2]string{TaskSummaryKVFindings, findings},
+		[2]string{TaskSummaryKVRemaining, stringsOr(v.Remaining, "")},
+		[2]string{TaskSummaryKVNextStep, stringsOr(v.NextStep, "")},
+	)
+	// 去掉空值骨架行，避免完成卡出现空白「正在做」。
+	compact := make([][2]string, 0, len(kv))
+	for _, pair := range kv {
+		if pair[1] == "" && (pair[0] == TaskSummaryKVFocus || pair[0] == TaskSummaryKVRemaining || pair[0] == TaskSummaryKVNextStep) {
+			continue
+		}
+		compact = append(compact, pair)
+	}
+	return []UINode{
+		{Type: UIMarkdown, Markdown: outcome},
+		{Type: UIKV, KV: compact},
+	}
+}
+
+// CardDisplaysFailed 判断卡是否应按失败展示：含 CardFailed，以及旧客户端
+// done + danger 兼容映射（U1 出口白名单）。
+func CardDisplaysFailed(status CardStatus, tone string) bool {
+	if status == CardFailed {
+		return true
+	}
+	return status == CardDone && tone == "danger"
+}
+
+func stringsOr(s, fallback string) string {
+	if s == "" {
+		return fallback
+	}
+	return s
+}

task_summary_test.go

@@ -0,0 +1,90 @@
+package core
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+)
+
+func TestTaskSummaryRunningBodyOmitsRawTaskAndUsesHonestPlaceholder(t *testing.T) {
+	v := TaskSummaryView{Focus: "核对需求与会议决定"}
+	body := v.RunningBody(TaskSummaryStatusQueued, [][2]string{{"材料键", "mk_x"}})
+	if len(body) != 2 || body[0].Type != UIMarkdown || body[1].Type != UIKV {
+		t.Fatalf("body shape = %+v", body)
+	}
+	if body[0].Markdown != TaskSummaryNoFindingsYet {
+		t.Fatalf("markdown = %q, want honest placeholder", body[0].Markdown)
+	}
+	rawTask := "逐页解析上传材料并对照验收条件" + strings.Repeat("x", 200)
+	if strings.Contains(body[0].Markdown, rawTask) {
+		t.Fatal("running body must not embed raw task text")
+	}
+	got := map[string]string{}
+	for _, kv := range body[1].KV {
+		got[kv[0]] = kv[1]
+	}
+	for _, key := range []string{TaskSummaryKVStatus, TaskSummaryKVFocus, TaskSummaryKVFindings, TaskSummaryKVRemaining, TaskSummaryKVNextStep, "材料键"} {
+		if _, ok := got[key]; !ok {
+			t.Fatalf("missing kv %q in %v", key, got)
+		}
+	}
+	if got[TaskSummaryKVStatus] != TaskSummaryStatusQueued {
+		t.Fatalf("status = %q", got[TaskSummaryKVStatus])
+	}
+	if got[TaskSummaryKVFindings] != TaskSummaryNoFindingsYet {
+		t.Fatalf("findings = %q", got[TaskSummaryKVFindings])
+	}
+}
+
+func TestTaskSummaryFinishedBodyFailureLabel(t *testing.T) {
+	v := TaskSummaryView{OutcomeLine: "执行失败：boom"}
+	body := v.FinishedBody(TaskSummaryStatusFailed, nil)
+	if body[0].Markdown != "执行失败：boom" {
+		t.Fatalf("outcome = %q", body[0].Markdown)
+	}
+	found := false
+	for _, kv := range body[1].KV {
+		if kv[0] == TaskSummaryKVStatus {
+			found = true
+			if kv[1] != TaskSummaryStatusFailed {
+				t.Fatalf("status = %q, want %q", kv[1], TaskSummaryStatusFailed)
+			}
+		}
+	}
+	if !found {
+		t.Fatal("missing status kv")
+	}
+}
+
+func TestTaskSummaryViewJSONRoundTrip(t *testing.T) {
+	in := TaskSummaryView{
+		Title: "核对三份材料", Focus: "核对需求", FindingsNote: TaskSummaryNoFindingsYet,
+		Remaining: "评审意见", NextStep: "整理冲突", OutcomeLine: "",
+	}
+	b, err := json.Marshal(in)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var out TaskSummaryView
+	if err := json.Unmarshal(b, &out); err != nil {
+		t.Fatal(err)
+	}
+	if out != in {
+		t.Fatalf("round-trip = %+v, want %+v", out, in)
+	}
+}
+
+func TestCardDisplaysFailed(t *testing.T) {
+	if !CardDisplaysFailed(CardFailed, "danger") {
+		t.Fatal("CardFailed should display failed")
+	}
+	if !CardDisplaysFailed(CardDone, "danger") {
+		t.Fatal("legacy done+danger should display failed")
+	}
+	if CardDisplaysFailed(CardDone, "ok") {
+		t.Fatal("done+ok must not display failed")
+	}
+	if CardDisplaysFailed(CardActive, "info") {
+		t.Fatal("active must not display failed")
+	}
+}