Merge pull request #3484 from deepseek-harness/fix/fork-resume-system-prompt

fix(web): avoid repeated system prompt on resume

.agents/notes/implemented/architecture/2026-08-09-client-conversation-node-assembly.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write .agents/notes/implemented/architecture/2026-08-09-client-conversation-node-assembly.md
-2026-08-09-client-conversation-node-assembly.md: 425975944f7b23575c4f716dee8754dc6b3ab54c
-2026-08-09-client-conversation-node-assembly.zh.md: 96439fa951cdc1d6abe397ee37661291c0f954a7
+2026-08-09-client-conversation-node-assembly.md: 50e11b04d6461e99cdddb8e5e2d94bf864228841
+2026-08-09-client-conversation-node-assembly.zh.md: 7be1cd1b7f356caf51b8003821369771b0a6e269

.agents/notes/implemented/architecture/2026-08-09-client-conversation-node-assembly.md

@@ -278,7 +278,7 @@ Page size, record packing, the number of history loads, and RAF coalescing affec
 |---|---|---|---|
 | Inbox | `none` | No Node | Recompute next-step ID state along the Reader chain when prepend supplies earlier splices; next-turn creates no Chat Context |
 | Message | Immediate by default | `user`, `steering`, or `context` | Window-gap repair can reclassify the same message key |
-| Request Prompt | Immediate by default | One `system-prompt` for every header carrying a non-empty system field | A step's first header anchors before its request messages; a later same-step series anchors after its surface rewrite; prepend of the preceding header can correct a partial-window anchor |
+| Request Prompt | Immediate by default | One non-empty `system-prompt` for the initial request, each explicit series, or a real system change | A step's first header anchors before its request messages; prepend can hide a conservatively rendered resume after its preceding header proves the system unchanged |
 | Assistant | RAF for scalar chunks and packed runs, immediate for final, none for pure usage/finish | Same-key `assistant-step` with running/settled/interrupted status | Scalar and packed reducers are equivalent; Matches support fallback without `step/start`; Location close produces interruption presentation |
 | Tool | Immediate by default | One recursive `tool-call` root containing all `subCalls` | A result-only history window supports fallback; running→settled retains its key |
 | Command | Immediate by default | Ordinary `command` or integrated `manual-compaction` | Checkpoint arrival may change the anchor without changing the Context key |
@@ -291,7 +291,7 @@ Page size, record packing, the number of history loads, and RAF coalescing affec
 
 Inbox demonstrates that every Event can be a start-only instantaneous-state Context; not every business requires a start/update pair. Reader links each next-step state to the prior same-kind Context instead of inventing a lifecycle ID for the entire Inbox. The state itself shares immutable pending splice nodes and one current claimed-batch Set, while unconsumed next-turn input remains outside Conversation because no Chat or Trajectory classification reads it.
 
-Request Prompt demonstrates shared pure interpretation without shared target State: Chat and Trajectory call `inspectRequestPrompt()` from their own Definitions. The function canonicalizes the full header and classifies model-visible system/tool differences; each target then chooses its own output. Chat materializes every header carrying a non-empty system field, including `series` snapshots that repeat an unchanged header for an explicitly declared series or a post-replacement request, while Trajectory retains the complete request fact and its change classification. Ordinary append-only later Turns do not write another unchanged header. The first header in a Step follows the provider envelope rather than the header Event position: step one uses the owning Turn start and later steps use their Step start, placing the system field before the request's user-role messages; a later header in the same Step stays at its own Event after the surface rewrite that began the new series. When the preceding header is outside a partial window, a non-`initial` header stays at its own Event until prepend supplies that predecessor. Every header is a full snapshot, so a first loaded `resume`, `change`, or `series` header can render its system field without fabricating a comparison to unloaded history.
+Request Prompt demonstrates shared pure interpretation without shared target State: Chat and Trajectory call `inspectRequestPrompt()` from their own Definitions. The function canonicalizes the full header and classifies model-visible system/tool differences; each target then chooses its own output. Chat materializes a non-empty initial system field, a real system change, and each `series` snapshot that explicitly begins a message series or follows a surface replacement. An unchanged `resume` remains in Trajectory and reconstruction state but does not repeat the visible Chat row once its predecessor is loaded. Ordinary append-only later Turns do not write another unchanged header. The first header in a Step follows the provider envelope rather than the header Event position: step one uses the owning Turn start and later steps use their Step start, placing the system field before the request's user-role messages; a later header in the same Step stays at its own Event after the surface rewrite that began the new series. When the preceding header is outside a partial window, a non-`initial` header stays at its own Event and renders conservatively. Prepending an identical predecessor hides an unchanged resume without withdrawing its stable Node key; a real change remains visible. Every header is a full snapshot, so a first loaded `resume`, `change`, or `series` header can render its system field without fabricating a comparison to unloaded history ([resume presentation decision](../bug-fix/2026-09-03-resume-headers-do-not-repeat-system-prompts.md)).
 
 Retry, Assistant, and Turn Tail demonstrate independent claims on one Event. Each Definition updates only its own State and produces its own atomic Chat Node.
 

.agents/notes/implemented/architecture/2026-08-09-client-conversation-node-assembly.zh.md

@@ -278,7 +278,7 @@ Chat `order` 的结构性变化仍可能重排当前可见 key；纯 data 更新
 |---|---|---|---|
 | Inbox | `none` | 不生成 Node | prepend 补前序 splice 时沿 Reader 链重算 next-step ID state；next-turn 不创建 Chat Context |
 | Message | 默认 immediate | `user`、`steering` 或 `context` | window gap 修复可让同一 message key 重新分类 |
-| Request Prompt | 默认 immediate | 每条带非空 system 字段的 header 都生成一个 `system-prompt` | Step 首条 header 锚定在请求消息之前；同 step 后续序列锚定在表层改写之后；prepend 补入前序 header 后可纠正部分窗口的锚点 |
+| Request Prompt | 默认 immediate | 初始请求、每个显式序列或真实 system 变化各生成一个非空 `system-prompt` | Step 首条 header 锚定在请求消息之前；prepend 补入前序 header 并证明 system 未变后，可隐藏此前保守渲染的 resume |
 | Assistant | scalar chunk 与 packed run 为 RAF，final immediate，纯 usage/finish 为 none | 同 key `assistant-step`，状态为 running/settled/interrupted | scalar 与 packed reducer 等价；缺 `step/start` 可先用 Matches fallback；Location close 生成中断表现 |
 | Tool | 默认 immediate | 一个递归 `tool-call` root，包含全部 `subCalls` | result-only 历史窗口可 fallback；running→settled 保持 key |
 | Command | 默认 immediate | 普通 `command` 或集成 `manual-compaction` | checkpoint 到达可改变 anchor，但不改变 Context key |
@@ -291,7 +291,7 @@ Chat `order` 的结构性变化仍可能重排当前可见 key；纯 data 更新
 
 Inbox 展示了“每条 Event 都是一个 start-only 瞬间态 Context”，不是所有业务都需要 start/update 配对。每个 next-step state 通过 Reader 与前一个同 kind Context 形成连续 fold，而非给整个 Inbox 人工制造生命周期 ID。state 自身共享不可变 pending splice 节点和一个当前 claimed-batch Set；未消费的 next-turn input 不进入 Conversation，因为 Chat 与 Trajectory 都不读取它来分类。
 
-Request Prompt 展示了如何在不共享 target State 的前提下共用纯解释逻辑：Chat 与 Trajectory 各自在自己的 Definition 中调用 `inspectRequestPrompt()`。该函数规范化完整 header，并判定面向模型的 system/tool 差异；随后每个 target 自行选择产物。Chat 会物化每条带非空 system 字段的 header，包括为显式声明的序列或表层替换后的请求重复未变 header 的 `series` 快照；Trajectory 则保留完整请求事实及其变化分类。普通的仅追加后续 Turn 不会再次写入未变 header。一个 Step 中的首条 header 遵循提供方信封，而不是 header Event 位置：step one 使用所属 Turn start，后续 step 使用各自的 Step start，把 system 字段放到该请求的 user-role 消息之前；同一 Step 的后续 header 保留在开启新序列的表层改写之后。部分窗口未包含前序 header 时，非 `initial` header 会保留在自身 Event，直到 prepend 补入该前序 header。每条 header 都是完整快照，因此已加载窗口中的首条 `resume`、`change` 或 `series` header 无需凭空构造与未加载历史的比较，也能渲染其 system 字段。
+Request Prompt 展示了如何在不共享 target State 的前提下共用纯解释逻辑：Chat 与 Trajectory 各自在自己的 Definition 中调用 `inspectRequestPrompt()`。该函数规范化完整 header，并判定面向模型的 system/tool 差异；随后每个 target 自行选择产物。Chat 会物化非空的初始 system 字段、真实 system 变化，以及每个显式开启消息序列或紧随表层替换的 `series` 快照。未变化的 `resume` 会留在 Trajectory 和重建状态中，但前序 header 已加载时不会重复可见的 Chat 行。普通的仅追加后续 Turn 不会再次写入未变 header。一个 Step 中的首条 header 遵循提供方信封，而不是 header Event 位置：step one 使用所属 Turn start，后续 step 使用各自的 Step start，把 system 字段放到该请求的 user-role 消息之前；同一 Step 的后续 header 保留在开启新序列的表层改写之后。部分窗口未包含前序 header 时，非 `initial` header 会保留在自身 Event 并保守渲染。prepend 补入相同的前序 header 后，内容未变的 resume 会隐藏但不撤回其稳定 Node key；真实变化仍然可见。每条 header 都是完整快照，因此已加载窗口中的首条 `resume`、`change` 或 `series` header 无需凭空构造与未加载历史的比较，也能渲染其 system 字段（[resume 展示决策](../bug-fix/2026-09-03-resume-headers-do-not-repeat-system-prompts.zh.md)）。
 
 Retry、Assistant 和 Turn Tail 展示了同一 Event 被多个 Definition 独立认领。每个 Definition 只更新自己的 State，最终分别生成原子 Chat Node。
 

.agents/notes/implemented/bug-fix/2026-09-03-resume-headers-do-not-repeat-system-prompts.i18n.yaml

@@ -0,0 +1,6 @@
+# Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
+# side as of the last confirmed-consistent state. Both languages carry equal authority;
+# after editing either side, bring the other along and re-record with:
+#   pnpm run verify-translation-pairing --write .agents/notes/implemented/bug-fix/2026-09-03-resume-headers-do-not-repeat-system-prompts.md
+2026-09-03-resume-headers-do-not-repeat-system-prompts.md: de5e509c9e57af35bc36c24004457f02b63fd99d
+2026-09-03-resume-headers-do-not-repeat-system-prompts.zh.md: 008e25d8d507aac8fbaec7230bad433732f0efd0

.agents/notes/implemented/bug-fix/2026-09-03-resume-headers-do-not-repeat-system-prompts.md

@@ -0,0 +1,31 @@
+# Agent Note: Resume headers do not repeat system prompts
+
+Status: implemented
+
+English | [中文](2026-09-03-resume-headers-do-not-repeat-system-prompts.zh.md)
+
+## Problem
+
+Forking a Session copies the source history into the child. The child's first model request then records a `request/header` with reason `resume`, even when its system field is identical to the preceding copied header. Chat treated every resume header as a new display point, so continuing the fork showed a second `System prompt` row and suggested that the system prompt had been injected twice. The provider request still carried the system field once; the duplicate existed only in Chat presentation.
+
+## Decision
+
+The durable resume header records the request boundary needed for exact Session reconstruction. Chat compares that full header with the preceding loaded Request Prompt and displays a non-empty system prompt only for the initial request, an explicit message-series start, or a real system-field change. An unchanged resume does not create a visible repetition.
+
+A partial history window may begin with a non-initial header and lack the predecessor needed for comparison. Chat renders that system prompt conservatively. If prepend later supplies an identical predecessor, the existing request-prompt Node becomes hidden instead of being withdrawn; its key and page-lifetime anchor stay stable. A different system field remains visible.
+
+Trajectory exposes every request header and its classified changes. Chat presentation does not alter provider requests, Session events, or reconstruction.
+
+## Alternatives considered
+
+**Omit unchanged resume headers from the Session log.** Rejected: resume is a real request boundary, and removing it would make exact reconstruction depend on process history that the durable log does not contain.
+
+**Special-case only forked Sessions.** Rejected: an ordinary process resume has the same presentation semantics, and the request headers already contain the system fields needed for a direct comparison.
+
+**Keep the duplicate row as a lifecycle marker.** Rejected: `System prompt` describes model-visible request content, so using it to mark a loop restart incorrectly implies another prompt injection. Request lifecycle evidence remains available in Trajectory.
+
+## Consequences
+
+Continuing a fork or resuming a process with an unchanged system field leaves one visible `System prompt` row for the current message series. Explicit series starts and real system changes still repeat the row. A partial window can initially show a conservative row and hide it after older history loads, while retaining the same materialized Node.
+
+The unit regression covers initial, series, unchanged resume, system-change, and prepend cases. The Web recorded-session scenario contains an unchanged resume header and asserts that the settled Chat renders exactly one `System prompt` control.

.agents/notes/implemented/bug-fix/2026-09-03-resume-headers-do-not-repeat-system-prompts.zh.md

@@ -0,0 +1,31 @@
+# Agent Note: Resume header 不重复系统提示词
+
+Status: implemented
+
+[English](2026-09-03-resume-headers-do-not-repeat-system-prompts.md) | 中文
+
+## 问题
+
+fork Session 会把源会话历史复制到子会话。即使 system 字段与前一条被复制的 header 完全相同，子会话的第一个模型请求仍会记录一条 reason 为 `resume` 的 `request/header`。Chat 把每条 resume header 都视作新的展示点，因此继续 fork 会显示第二行`系统提示词`，让人误以为系统提示词被注入了两次。提供方请求实际仍只携带一次 system 字段；重复仅存在于 Chat 展示中。
+
+## 决策
+
+持久化 resume header 记录精确重建 Session 所需的请求边界。Chat 会把完整 header 与前一条已加载 Request Prompt 比较，只在初始请求、显式消息序列起点或真实 system 字段变化时显示非空系统提示词。内容未变的 resume 不创建可见的重复行。
+
+部分历史窗口可能以非初始 header 开头，因缺少前序 header 而无法比较。Chat 会保守渲染该系统提示词。如果 prepend 随后补入相同的前序 header，既有 request-prompt Node 会转为隐藏而不是被撤回；其 key 和页面生命周期内的 anchor 保持稳定。不同的 system 字段仍然可见。
+
+Trajectory 会展示每一条请求 header 及其变化分类。Chat 展示不会改变提供方请求、Session event 或重建行为。
+
+## 考虑过的替代方案
+
+**从 Session log 省略未变化的 resume header。** 否决：resume 是真实的请求边界，移除后精确重建将依赖持久日志未记录的进程历史。
+
+**只对 fork Session 做特殊处理。** 否决：普通进程恢复具有相同的展示语义，请求 header 已经包含可直接比较的 system 字段。
+
+**把重复行保留为生命周期标记。** 否决：`系统提示词`描述模型可见的请求内容，用它标记 loop 重启会错误暗示再次注入提示词。请求生命周期证据仍可在 Trajectory 中查看。
+
+## 后果
+
+继续 fork 或在 system 字段未变时恢复进程，当前消息序列只保留一行可见的`系统提示词`。显式序列起点与真实 system 变化仍会重复该行。部分窗口起初可以显示保守行，并在更早历史加载后将其隐藏，同时保留同一个已物化 Node。
+
+单元回归覆盖初始请求、显式序列、未变化 resume、system 变化与 prepend 场景。Web 录制会话场景包含一条未变化的 resume header，并断言稳定后的 Chat 只渲染一个`系统提示词`控件。

apps/web/tests/chat-long-interactions.e2e.ts

@@ -173,6 +173,10 @@ describe('web e2e: long Chat interaction contract', () => {
 
   it.skipIf(MODE === 'record')('keeps heterogeneous rows and their actions bound to exact semantic identities', async () => {
     onTestFailed(() => saveFailureShot(page, 'web-e2e-chat-long-interactions'))
+    await expect.poll(
+      () => scaffold.ctx.agents.get(SessionId(SESSION_ID)) !== undefined,
+      { timeout: 10_000 },
+    ).toBe(true)
     const source = scaffold.ctx.agents.get(SessionId(SESSION_ID))
     if (source === undefined) throw new Error('seeded long-history agent is not attached')
 

apps/web/tests/message-actions.e2e.ts

@@ -1,7 +1,8 @@
 // Web e2e scenario: message IconActions + clocks. Cold-seeds a deterministic
-// completed-turn-tail fork case (zero model calls) and pins the settled
-// conversation aria after the footers are focus-revealed — the surface package
-// jsdom tests cannot substitute for (docs/testing.md snapshot rule).
+// completed-turn-tail fork case with an unchanged resume header (zero model
+// calls) and pins the settled conversation aria after the footers are
+// focus-revealed — the surface package jsdom tests cannot substitute for
+// (docs/testing.md snapshot rule).
 import { mkdir, readFile, writeFile } from 'node:fs/promises'
 import { join } from 'node:path'
 import { fileURLToPath } from 'node:url'
@@ -70,6 +71,10 @@ function completedTailFixture(raw: string): string {
       },
     }
   })
+  const inheritedHeader = kept.findLast(event => event.type === 'request/header')
+  if (inheritedHeader?.type !== 'request/header') {
+    throw new Error('borrowed recording has no request header')
+  }
   let seq = (kept.at(-1)?.seq ?? -1) + 1
   let time = (kept.at(-1)?.time ?? -1) + 1
   const at = (event: Record<string, unknown>): { seq: number; time: number } & Record<string, unknown> => ({
@@ -109,6 +114,7 @@ function completedTailFixture(raw: string): string {
       surfaceOp: 'append',
     }),
     at({ type: 'step/start', data: { turn: 2, step: 1 } }),
+    at({ type: 'request/header', data: { header: inheritedHeader.data.header, reason: 'resume' } }),
     at({
       type: 'assistant/message',
       data: {
@@ -149,6 +155,9 @@ describe('web e2e: message IconActions and clocks on settled history', () => {
     await writeFile(join(sessionCwd, 'b.txt'), 'beta\n')
     const raw = completedTailFixture(await readFile(SEED, 'utf8'))
     expect(fixtureUserPrompts(raw), 'adapted seed must carry both prompts').toEqual([PROMPT, SECOND_PROMPT])
+    expect(parseSeedFixture(raw).events.flatMap(event => event.type === 'request/header'
+      ? [event.data.reason]
+      : []), 'adapted seed must carry an unchanged resume header').toEqual(['initial', 'resume'])
     await seedSession(scaffold, raw, SEED_ID)
     browser = await chromium.launch()
     page = await newEnglishPage(browser)
@@ -172,6 +181,10 @@ describe('web e2e: message IconActions and clocks on settled history', () => {
     await sessionRow.click()
     await expect.poll(() => page.getByText(MID_TURN_TEXT, { exact: true }).count(), { timeout: 15_000 }).toBe(1)
     await expect.poll(() => page.getByText('DONE', { exact: true }).count(), { timeout: 15_000 }).toBe(1)
+    await expect.poll(
+      () => page.getByRole('button', { name: 'System prompt', exact: true }).count(),
+      { timeout: 10_000 },
+    ).toBe(1)
 
     // Focus-reveal the footers (hover:hover keeps them opacity-hidden until
     // hover/focus-within). Branch renders only under assistant answers — user

packages/client/ui-chat/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-chat/README.md
-README.md: 79214bf2feb8384cecbb152aa31af162dc6dfdde
-README.zh.md: 674959e1974c74abba75f179eff50fe8488458fc
+README.md: 5a557f2a2125bddfe18631359665d6fa5e998458
+README.zh.md: 2fc241ad71e35eb54afcf4dde38c361248848d5f

packages/client/ui-chat/README.md

@@ -25,7 +25,7 @@ The browser Chat target for Conversation assembly. It registers Chat event defin
 <a id="system-prompt-row"></a>
 ## System prompt row
 
-Chat shows a collapsed `System prompt` row for each non-empty initial or resumed request, explicit message-series start, or real system-field change. It does not repeat the row for same-series config-only or tool-only changes, tool steps, or retries. The row appears before that request's user messages, matching the provider envelope, and expands to the exact model-visible text with its original line breaks. A partial history window renders a non-initial header conservatively until the preceding page arrives; a header without a system prompt creates no row.
+Chat shows a collapsed `System prompt` row for a non-empty initial request, explicit message-series start, real system-field change, or non-initial request whose preceding header is outside the loaded history window. Once that predecessor is available, an unchanged resume does not repeat the row; same-series config-only or tool-only changes, tool steps, and retries also create no repetition. The row appears before that request's user messages, matching the provider envelope, and expands to the exact model-visible text with its original line breaks. A header without a system prompt creates no row.
 
 -----
 

packages/client/ui-chat/README.zh.md

@@ -25,7 +25,7 @@ Conversation 组装的浏览器 Chat target。本包注册 Chat event definition
 <a id="system-prompt-row"></a>
 ## 系统提示词行
 
-Chat 会为每个非空的初始或恢复请求、显式消息序列起点或真实 system 字段变化显示一行默认折叠的`系统提示词`。同一序列内仅配置或仅工具变化、工具步骤与重试不会重复该行。该行位于请求的用户消息之前，与提供方 envelope 顺序一致；展开后显示保留原始换行的精确模型可见文本。历史窗口不完整时，非初始 header 会保守显示，直到前一页到达；没有系统提示词的 header 不创建该行。
+Chat 会为非空的初始请求、显式消息序列起点、真实 system 字段变化，或前序 header 尚未进入已加载历史窗口的非初始请求显示一行默认折叠的`系统提示词`。前序 header 到达后，内容未变的 resume 不会重复该行；同一序列内仅配置或仅工具变化、工具步骤与重试也不会重复。该行位于请求的用户消息之前，与提供方 envelope 顺序一致；展开后显示保留原始换行的精确模型可见文本。没有系统提示词的 header 不创建该行。
 
 -----
 

packages/client/ui-chat/src/client/conversation-nodes/request-prompt.ts

@@ -78,7 +78,7 @@ export function requestPromptDefinition(inspect: RequestPromptInspector): Conver
           match.event.data.reason === 'initial',
         ),
         showsPrompt: previous === undefined
-          || match.event.data.reason !== 'change'
+          || match.event.data.reason === 'series'
           || match.event.data.startsSeries === true
           || change === 'system'
           || change === 'system-and-tools',
@@ -89,8 +89,17 @@ export function requestPromptDefinition(inspect: RequestPromptInspector): Conver
     update: context => context.state,
     buildViewNode: (context) => {
       const state = context.state
-      if (state === undefined || !state.showsPrompt || state.prompt.system === '') return null
-      return chatNode(context, 'system-prompt', state.anchorSeq, { text: state.prompt.system })
+      if (state === undefined) return null
+      const current = context.current.get('chat') as ChatNode | null | undefined
+      const visible = state.showsPrompt && state.prompt.system !== ''
+      if (!visible && current?.kind !== 'system-prompt') return null
+      return chatNode(
+        context,
+        'system-prompt',
+        state.anchorSeq,
+        { text: state.prompt.system },
+        { visibility: visible ? 'visible' : 'hidden' },
+      )
     },
   }
 }

packages/client/ui-chat/tests/conversation-node-definitions.client.spec.ts

@@ -1402,7 +1402,7 @@ describe('built-in conversation node Definitions', () => {
     })
   })
 
-  it('materializes series starts and system changes but not same-series config or tool changes', () => {
+  it('materializes series starts and system changes but not unchanged resumes, config, or tool changes', () => {
     const tools = [{ name: 'read', description: 'Read', parameters: { type: 'object' } }]
     const expandedTools = [...tools, { name: 'write', description: 'Write', parameters: { type: 'object' } }]
     const value = assembler([
@@ -1458,7 +1458,6 @@ describe('built-in conversation node Definitions', () => {
     expect(prompts.map(prompt => ({ anchorSeq: prompt.anchorSeq, data: prompt.data }))).toEqual([
       { anchorSeq: 1, data: { text: '# Initial' } },
       { anchorSeq: 4, data: { text: '# Initial' } },
-      { anchorSeq: 5, data: { text: '# Initial' } },
       { anchorSeq: 6, data: { text: '# Updated' } },
     ])
 
@@ -1480,18 +1479,20 @@ describe('built-in conversation node Definitions', () => {
     windowed.prepend([
       at(5, 'request/header', {
         reason: 'initial',
-        header: { config: { provider: 'fake', model: 'fake' }, system: '# Original prompt' },
+        header: { config: { provider: 'fake', model: 'fake' }, system: '# Resumed prompt' },
       }),
     ], false)
     windowed.flush()
     const restored = snapshot(windowed)
-    const restoredPrompts = restored.order.flatMap((key) => {
-      const candidate = restored.nodes.get(key)
-      return candidate?.kind === 'system-prompt' ? [candidate] : []
-    })
-    expect(restoredPrompts.map(prompt => prompt.data)).toEqual([
-      { text: '# Original prompt' },
-      { text: '# Resumed prompt' },
+    const restoredPrompts = restored.nodes.values()
+      .filter(candidate => candidate.kind === 'system-prompt')
+    expect(restoredPrompts.map(prompt => ({
+      anchorSeq: prompt.anchorSeq,
+      visibility: prompt.visibility,
+      data: prompt.data,
+    })).sort((left, right) => left.anchorSeq - right.anchorSeq)).toEqual([
+      { anchorSeq: 5, visibility: 'visible', data: { text: '# Resumed prompt' } },
+      { anchorSeq: 10, visibility: 'hidden', data: { text: '# Resumed prompt' } },
     ])
   })
 

snapshots/web/subagent-conversation/ui-expanded.expected.md

@@ -47,12 +47,7 @@
 - button "Ran for {{duration}}":
   - img
   - text: Ran for {{duration}}
-- text: {{clock}}
-- button "System prompt":
-  - img
-  - img
-  - text: System prompt
-- text: Now give the same explanation to a human reader. {{clock}}
+- text: {{clock}} Now give the same explanation to a human reader. {{clock}}
 - button "Copy":
   - img
 - button "Thought for a while" [expanded]:

snapshots/web/subagent-conversation/ui.expected.md

@@ -39,12 +39,7 @@
 - button "Ran for {{duration}}":
   - img
   - text: Ran for {{duration}}
-- text: {{clock}}
-- button "System prompt":
-  - img
-  - img
-  - text: System prompt
-- text: Now give the same explanation to a human reader. {{clock}}
+- text: {{clock}} Now give the same explanation to a human reader. {{clock}}
 - button "Copy":
   - img
 - button "Thought for a while":