fix(pty): fence delayed signal prompts

.agents/notes/implemented/architecture/2026-07-28-portable-execution-world-consumers.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/2026-07-28-portable-execution-world-consumers.md
-2026-07-28-portable-execution-world-consumers.md: 715529e5f24df0c2fe0afc40716737285afa223b
-2026-07-28-portable-execution-world-consumers.zh.md: a9d864b581bd546c12776152ad4515816ee6b83a
+2026-07-28-portable-execution-world-consumers.md: 54b8ec19bc74e734f2cb940a475d2c7b4c9336fd
+2026-07-28-portable-execution-world-consumers.zh.md: f21be00fd35267fe93e2fbb62642809cc42c0742

.agents/notes/implemented/architecture/2026-07-28-portable-execution-world-consumers.md

@@ -22,7 +22,7 @@ Generic consumers use that execution world:
 
 - `dsh-bash-local` continues to map Bash semantics onto ordinary `ctx.subprocess.spawn()`.
 - `dsh-lsp-local` reads and contains source through `ctx.fs`, resolves and launches language servers through `ctx.subprocess`, and carries provider-owned file URIs through initialization and result rendering. Its JSON-RPC, pooling, synchronization, cancellation, and normalization stay unchanged.
-- `dsh-pty-local` maps persistent-shell semantics onto `ctx.subprocess.spawnTerminal()`. The local `node-pty` and process-inspection implementation moves into `dsh-subprocess-local`; another subprocess provider supplies the same primitive. The allocation signal is detached before publication, while readiness initialization retains setup cancellation. Prompt and silence evidence collected during asynchronous pre-write inspection is discarded when the provider write begins. Cancellation retains the send reservation until asynchronous foreground signalling settles, so the signal cannot target a successor; a timed-out asynchronous write, or a signal failure during that write, retains the reservation until the provider settles the write. Completion of a stale inspection resumes polling for the current send.
+- `dsh-pty-local` maps persistent-shell semantics onto `ctx.subprocess.spawnTerminal()`. The local `node-pty` and process-inspection implementation moves into `dsh-subprocess-local`; another subprocess provider supplies the same primitive. The allocation signal is detached before publication, while readiness initialization retains setup cancellation. Prompt and silence evidence collected during asynchronous pre-write inspection is discarded when the provider write begins. Cancellation retains the send reservation until asynchronous foreground signalling settles, so the signal cannot target a successor; if a signaled send returns `inferred_idle` before its prompt arrives, that marker remains attributed to the prior send instead of settling a successor after its echo. A timed-out asynchronous write, or a signal failure during that write, retains the reservation until the provider settles the write. Completion of a stale inspection resumes polling for the current send.
 - `dsh-code-runtime-subprocess` materializes a dependency-free runner through `ctx.fs` and launches it through `ctx.subprocess`, preserving the Code Runtime binding and output contract across local or remote worlds. It shares host-side worker mechanics through the non-plugin `dsh-code-runtime-worker/runtime-host` subpath instead of copying them. Preparation carries one lifecycle signal through filesystem resolution, materialization, and executable lookup so disposal can abort a stalled provider. The heap-bounded worker rejects oversized binding frames before transfer, each outer hop enforces the same bound before serialization, and the launcher publishes an accepted terminal frame before reaping its controller so a descendant that inherits controller pipes cannot suppress completion; the host still awaits process-group quiescence.
 
 `dsh-code-runtime-worker` remains a separate implementation. It is the smaller in-process backend and works in single-file distributions that cannot assume an installed Node executable. Remote filesystem/process compositions select `dsh-code-runtime-subprocess`; they do not need a provider-specific Code Runtime package.

.agents/notes/implemented/architecture/2026-07-28-portable-execution-world-consumers.zh.md

@@ -22,7 +22,7 @@ Status: implemented
 
 - `dsh-bash-local` 继续把 Bash 语义映射到普通的 `ctx.subprocess.spawn()`。
 - `dsh-lsp-local` 通过 `ctx.fs` 读取源文件并验证包含关系，通过 `ctx.subprocess` 解析和启动语言服务器，并让由提供方负责的文件 URI 贯穿初始化与结果渲染。其 JSON-RPC、池化、同步、取消和规范化保持不变。
-- `dsh-pty-local` 把持久 shell 语义映射到 `ctx.subprocess.spawnTerminal()`。本地 `node-pty` 与进程检查实现移入 `dsh-subprocess-local`；其他进程管理提供方则提供相同原语。分配信号会在发布前解除关联，而就绪初始化仍保留设置阶段的取消。提供方开始写入时，系统会丢弃异步写入前检查期间收集的提示符与静默证据。取消会保留发送预留，直至异步前台信号发送结算，从而使该信号无法把后续发送作为目标；异步写入超时，或该写入期间发生信号发送失败，都会保留预留，直至提供方将写入结算。陈旧检查完成后，会针对当前发送恢复轮询。
+- `dsh-pty-local` 把持久 shell 语义映射到 `ctx.subprocess.spawnTerminal()`。本地 `node-pty` 与进程检查实现移入 `dsh-subprocess-local`；其他进程管理提供方则提供相同原语。分配信号会在发布前解除关联，而就绪初始化仍保留设置阶段的取消。提供方开始写入时，系统会丢弃异步写入前检查期间收集的提示符与静默证据。取消会保留发送预留，直至异步前台信号发送结算，从而使该信号无法把后续发送作为目标；如果收到信号的 send 在其提示符到达前返回 `inferred_idle`，随后到达的标记仍归属于先前的 send，而不会在后续 send 回显后使其完成。异步写入超时，或该写入期间发生信号发送失败，都会保留预留，直至提供方将写入结算。陈旧检查完成后，会针对当前发送恢复轮询。
 - `dsh-code-runtime-subprocess` 通过 `ctx.fs` 物化无依赖 runner，并通过 `ctx.subprocess` 启动它，从而在本地或远程执行世界中保留代码运行时的绑定与输出契约。它通过非插件子路径 `dsh-code-runtime-worker/runtime-host` 共享宿主侧 worker 机制，而不是复制这些机制。准备阶段让同一个生命周期信号贯穿文件系统解析、物化和可执行文件查找，使资源释放能够中止停滞的提供方操作。受堆上限约束的 worker 会在传输前拒绝过大的绑定帧；每个外层转发环节都会在序列化前执行相同的上限检查；launcher 会在回收 controller 前发布已接纳的终态帧，使继承 controller 管道的后代进程无法阻止完成；宿主仍会等待进程组完全停稳。
 
 `dsh-code-runtime-worker` 仍是独立实现。它是较小的进程内后端，可用于无法假定已安装 Node 可执行文件的单文件分发。远程文件系统／进程组合选择 `dsh-code-runtime-subprocess`；它们不需要提供方专用的代码运行时包。

packages/pty/pty-local/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/pty/pty-local/README.md
-README.md: 7e31adfbc486a190252be867e2113948b17e7924
-README.zh.md: eb628aef9ad6b0fea14a5e833197b4fac7856785
+README.md: c7b7a363f22821363a0fed81982165fd35326d12
+README.zh.md: 859b94e4f29b82abb298468f028f9eba7cc067e6

packages/pty/pty-local/README.md

@@ -8,7 +8,7 @@ Persistent shell backend for `ctx.pty` over `ctx.subprocess.spawnTerminal`. It s
 
 The plugin injects `pty`, `sandbox`, `sandboxPolicy`, and `subprocess`, then registers the configured backend type (`shell`). `danger-full-access` starts the shell directly; confined modes wrap the exact shell argv through `ctx.sandbox`. The effective session mode is resolved at spawn. A change to a different effective mode is rejected before its `sandbox/mode` event commits while that owner has an open PTY or a spawn in progress; the fence is attached to the exact owner and therefore outlives a provider reload that retains existing sessions. Wait for creation to settle and close the sessions before changing modes, so a terminal opened with wider access cannot survive a downgrade.
 
-Readiness combines a foreground-verified private bash prompt marker, provider-reported foreground stdin-wait facts, silence fallback, and absolute timeout. A marker is not ready until the printable tail after the latest owned marker exactly equals the controlled `PS1`, including when the OSC marker and prompt are split across data callbacks; echoed input or output following a delayed earlier prompt therefore cannot settle the current send. Prompt and silence evidence collected before the provider write, including while pre-write foreground inspection is pending, is discarded at the write boundary. When bash prints the marker before the terminal provider publishes its return to the foreground process group, polling retains the candidate for `handoffGraceMs` past the ordinary silence bound so a coincident handoff can win. An interactive child that inherits `PROMPT_COMMAND` therefore cannot suppress inferred-idle readiness until the absolute timeout. Unknown foreground state is never a positive exact-idle signal. A foreground group's stdin wait that existed before a send is likewise not post-write readiness: the same group must be observed outside that wait before a later wait can settle the send, while a changed foreground group is new evidence. During unpublished startup, a fallback requires observed output; zero-output silence cannot publish an empty session, and timeout rejects the spawn. Cancellation closes the unpublished shell and rejects with the caller's exact abort reason; `PtyBackendCleanupError` separately preserves a cleanup failure. The terminal-allocation signal is detached when allocation returns, while readiness initialization keeps the setup signal, so later cancellation cannot terminate a published persistent session. Incomplete terminal-control sequences are bounded by `maxReadBytes` and discarded through their terminator after crossing that limit; a trailing carriage return is carried across callbacks so split CRLF becomes one newline.
+Readiness combines a foreground-verified private bash prompt marker, provider-reported foreground stdin-wait facts, silence fallback, and absolute timeout. A marker is not ready until the printable tail after the latest owned marker exactly equals the controlled `PS1`, including when the OSC marker and prompt are split across data callbacks; echoed input or output following a delayed earlier prompt therefore cannot settle the current send. After a signaled send returns `inferred_idle` without a prompt marker, the next marker remains attributed to that prior send and cannot settle a successor even when it follows the successor's echoed input. Prompt and silence evidence collected before the provider write, including while pre-write foreground inspection is pending, is discarded at the write boundary. When bash prints the marker before the terminal provider publishes its return to the foreground process group, polling retains the candidate for `handoffGraceMs` past the ordinary silence bound so a coincident handoff can win. An interactive child that inherits `PROMPT_COMMAND` therefore cannot suppress inferred-idle readiness until the absolute timeout. Unknown foreground state is never a positive exact-idle signal. A foreground group's stdin wait that existed before a send is likewise not post-write readiness: the same group must be observed outside that wait before a later wait can settle the send, while a changed foreground group is new evidence. During unpublished startup, a fallback requires observed output; zero-output silence cannot publish an empty session, and timeout rejects the spawn. Cancellation closes the unpublished shell and rejects with the caller's exact abort reason; `PtyBackendCleanupError` separately preserves a cleanup failure. The terminal-allocation signal is detached when allocation returns, while readiness initialization keeps the setup signal, so later cancellation cannot terminate a published persistent session. Incomplete terminal-control sequences are bounded by `maxReadBytes` and discarded through their terminator after crossing that limit; a trailing carriage return is carried across callbacks so split CRLF becomes one newline.
 
 Send cancellation marks queued input as canceled before asking the terminal handle to signal the current foreground process group with a real `SIGINT`; if asynchronous pre-write inspection later settles, it cannot execute that input. The canceled send retains its slot until foreground signalling settles, so a successor cannot become that signal's target. Cancellation never emulates interruption by writing `\x03`, so raw-mode programs remain cancellable. A send that times out during an asynchronous provider write, or whose cancellation signal fails while that write remains pending, reports its result but retains the slot until the write settles, so late bytes cannot interleave with a successor. Close starts provider-owned TERM-to-KILL whole-session cleanup and awaits quiescence after the terminal outcome. A cleanup failure does not cache a permanently rejected close; a later close retries the provider operation.
 

packages/pty/pty-local/README.zh.md

@@ -8,7 +8,7 @@
 
 该插件注入 `pty`、`sandbox`、`sandboxPolicy` 和 `subprocess`，然后注册所配置的后端类型（`shell`）。`danger-full-access` 会直接启动 shell；受限模式则通过 `ctx.sandbox` 包装确切的 shell argv。系统在 spawn 时解析会话的实际模式。当某个所有者存在开放的 PTY 或正在进行 spawn 时，如果配置变更会得到不同的实际模式，系统会在对应 `sandbox/mode` 事件提交前拒绝该变更。该限制绑定到确切所有者，因此即使提供方重新加载并保留现有会话，它仍然有效。更改模式前，请等待创建结算并关闭会话，避免以更宽权限打开的终端在权限降级后继续存在。
 
-就绪检测结合以下机制：由前台状态验证的私有 bash 提示符标记、提供方报告的前台 stdin 等待事实、静默回退和绝对超时。只有最近一个自有标记之后的可打印尾部与受控 `PS1` 完全相等时，系统才会把标记视为就绪；即使 OSC 标记和提示符被拆到多个数据回调中也是如此。因此，如果回显的输入或输出跟在延迟到达的先前提示符之后，该提示符无法使当前 send 完成。系统会在写入边界丢弃提供方写入前收集的提示符与静默证据，包括写入前的前台检查尚未完成时收集的证据。如果 bash 在终端提供方发布其重新取得前台进程组的状态前打印标记，轮询会在普通静默上限之后再保留该候选状态 `handoffGraceMs`，使恰好同时发生的前台交接有机会胜出。因此，继承 `PROMPT_COMMAND` 的交互式子进程无法持续压制推断空闲就绪，最多只能延续到绝对超时。未知的前台状态绝不会作为精确空闲的正向信号。同样，一次 send 之前就已存在的前台进程组 stdin 等待并不代表写入后就绪：必须先观察到同一进程组脱离该等待，之后再次进入等待才能使该次 send 完成；前台进程组发生变化则构成新的证据。尚未发布的启动过程中，回退路径要求已经观察到输出；零输出静默不能发布空会话，超时则拒绝 spawn。取消操作会关闭尚未发布的 shell，并以调用方提供的确切中止原因拒绝；`PtyBackendCleanupError` 会单独保留清理失败。终端分配返回时，分配信号会解除关联；就绪初始化则保留设置阶段信号，因此后续取消无法终止已发布的持久会话。未完成的终端控制序列受 `maxReadBytes` 限制；超过上限后，系统会丢弃内容直到其终止符。末尾的回车会跨回调保留，使拆分的 CRLF 合并为一个换行。
+就绪检测结合以下机制：由前台状态验证的私有 bash 提示符标记、提供方报告的前台 stdin 等待事实、静默回退和绝对超时。只有最近一个自有标记之后的可打印尾部与受控 `PS1` 完全相等时，系统才会把标记视为就绪；即使 OSC 标记和提示符被拆到多个数据回调中也是如此。因此，如果回显的输入或输出跟在延迟到达的先前提示符之后，该提示符无法使当前 send 完成。在一次经过信号处理的 send 未出现提示符标记却返回 `inferred_idle` 后，下一个标记仍归属于该先前 send；即使该标记出现在后续 send 的输入回显之后，也不能使后续 send 完成。系统会在写入边界丢弃提供方写入前收集的提示符与静默证据，包括写入前的前台检查尚未完成时收集的证据。如果 bash 在终端提供方发布其重新取得前台进程组的状态前打印标记，轮询会在普通静默上限之后再保留该候选状态 `handoffGraceMs`，使恰好同时发生的前台交接有机会胜出。因此，继承 `PROMPT_COMMAND` 的交互式子进程无法持续压制推断空闲就绪，最多只能延续到绝对超时。未知的前台状态绝不会作为精确空闲的正向信号。同样，一次 send 之前就已存在的前台进程组 stdin 等待并不代表写入后就绪：必须先观察到同一进程组脱离该等待，之后再次进入等待才能使该次 send 完成；前台进程组发生变化则构成新的证据。尚未发布的启动过程中，回退路径要求已经观察到输出；零输出静默不能发布空会话，超时则拒绝 spawn。取消操作会关闭尚未发布的 shell，并以调用方提供的确切中止原因拒绝；`PtyBackendCleanupError` 会单独保留清理失败。终端分配返回时，分配信号会解除关联；就绪初始化则保留设置阶段信号，因此后续取消无法终止已发布的持久会话。未完成的终端控制序列受 `maxReadBytes` 限制；超过上限后，系统会丢弃内容直到其终止符。末尾的回车会跨回调保留，使拆分的 CRLF 合并为一个换行。
 
 取消发送会先把排队输入标记为已取消，再请求终端句柄向当前前台进程组发送真正的 `SIGINT`；如果异步的写入前检查随后才结算，也无法执行该输入。被取消的发送会保留其槽位，直至前台信号发送结算，因此后续发送不会成为该信号的目标。取消绝不会通过写入 `\x03` 模拟中断，因此原始模式程序仍可取消。发送在提供方异步写入期间超时，或在该写入仍未完成时其取消信号发送失败，都会报告各自结果，但继续占用该槽位，直至写入结算，从而避免延迟到达的字节与后续发送交错。关闭操作启动由提供方负责的 TERM→KILL 全会话清理，并在终端结果之后等待完全停稳。清理失败不会缓存成永久拒绝的关闭操作；后续关闭会重试提供方操作。
 

packages/pty/pty-local/src/session.ts

@@ -166,6 +166,7 @@ export class LocalPtySession implements PtyBackendSession {
   private activeDeadlineTimer: NodeJS.Timeout | undefined
   private activeAbort: (() => void) | undefined
   private readonly terminalOperations = new Set<Promise<void>>()
+  private signaledOperation: LocalSendOperation | undefined
   private interrupting: LocalSendOperation | undefined
   private writing: LocalSendOperation | undefined
   private pollingReady: LocalSendOperation | undefined
@@ -173,6 +174,7 @@ export class LocalPtySession implements PtyBackendSession {
   private promptSeen = false
   private promptTextSeen = false
   private promptTail = ''
+  private delayedSignaledPrompt = false
   private shellPgid: number | undefined
   private initializing = false
   private lastOutputAt = Date.now()
@@ -317,6 +319,7 @@ export class LocalPtySession implements PtyBackendSession {
   }
 
   async signal(signal: PtySignal): Promise<PtySignalResult> {
+    if (this.active !== undefined) this.signaledOperation = this.active
     const targetPgid = await this.terminal.signalForeground(signal)
     return { delivered: true, targetPgid }
   }
@@ -365,7 +368,9 @@ export class LocalPtySession implements PtyBackendSession {
   private onData(data: string): void {
     const sanitized = this.sanitizer.push(data)
     this.appendOutput(sanitized.text)
-    if (sanitized.prompt) {
+    if (sanitized.prompt && this.delayedSignaledPrompt) {
+      this.delayedSignaledPrompt = false
+    } else if (sanitized.prompt) {
       // Bash can print PROMPT_COMMAND before the kernel publishes its return
       // to the foreground process group. Retain the marker; polling below is
       // the authority that accepts it only after bash owns the foreground.
@@ -461,6 +466,13 @@ export class LocalPtySession implements PtyBackendSession {
   private settleActive(waitReason: PtyWaitReason, retainOwnership = false): void {
     const operation = this.active
     if (operation === undefined) return
+    // A signaled command can return by silence before bash emits its prompt.
+    // Reserve that marker so it cannot become successor readiness after echo.
+    const signaled = this.signaledOperation === operation
+    if (signaled) this.signaledOperation = undefined
+    if (waitReason === 'inferred_idle' && !this.promptSeen && signaled) {
+      this.delayedSignaledPrompt = true
+    }
     const scrollbackTruncated = this.scrollback.snapshot().truncated
     if (retainOwnership) {
       this.stopPolling()
@@ -486,6 +498,7 @@ export class LocalPtySession implements PtyBackendSession {
     this.activeAbort?.()
     this.activeAbort = undefined
     if (this.interrupting === operation) this.interrupting = undefined
+    if (this.signaledOperation === operation) this.signaledOperation = undefined
     this.writing = undefined
     this.pollingReady = undefined
     this.active = undefined
@@ -506,6 +519,7 @@ export class LocalPtySession implements PtyBackendSession {
 
   private interrupt(operation: LocalSendOperation): void {
     if (this.active !== operation) return
+    this.signaledOperation = operation
     this.interrupting = operation
     this.stopPolling()
     this.ownTerminalOperation(this.interruptOnce(operation))

packages/pty/pty-local/tests/session.spec.ts

@@ -591,6 +591,35 @@ describe('LocalPtySession readiness and output', () => {
     expect(await operation.done).toMatchObject({ waitReason: 'stdin_read' })
   })
 
+  it('does not attribute a post-echo prompt from an inferred prior send to its successor', async () => {
+    vi.useFakeTimers()
+    const terminal = new FakeTerminal()
+    const session = new LocalPtySession(terminal, config({ idleSilenceMs: 50, timeoutMs: 200 }))
+    await initialize(session, terminal)
+
+    const interrupted = session.startSend({ text: 'sleep', submit: true })
+    await Promise.resolve()
+    await Promise.resolve()
+    await session.signal('SIGINT')
+    await vi.advanceTimersByTimeAsync(50)
+    expect((await interrupted.done).waitReason).toBe('inferred_idle')
+
+    const successor = session.startSend({ text: "printf 'PID=%s\\n' \"$!\"", submit: true })
+    let settled = false
+    void successor.done.then(() => { settled = true })
+    await Promise.resolve()
+    await Promise.resolve()
+    terminal.emitData('printf \'PID=%s\\n\' "$!"\r\n\x1b]133;D;130\x07dsh> ')
+    await vi.advanceTimersByTimeAsync(10)
+    expect(settled).toBe(false)
+
+    terminal.emitData('PID=123\r\n\x1b]133;D;0\x07dsh> ')
+    await vi.advanceTimersByTimeAsync(10)
+    const result = await successor.done
+    expect(result.waitReason).toBe('stdin_read')
+    expect(result.viewport).toContain('PID=123')
+  })
+
   it('retains a prompt marker until the startup shell regains the foreground group', async () => {
     vi.useFakeTimers()
     const terminal = new FakeTerminal()