fix(agent): preserve thrown error values

.agents/notes/implemented/bug-fix/2026-07-20-error-cause-chain-diagnostics.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
-2026-07-20-error-cause-chain-diagnostics.md: 391e35997bb1bb050dd2ca620920961d77bb1c46
-2026-07-20-error-cause-chain-diagnostics.zh.md: 90d6559a9410e8a4e5475db9560a2a177ba7a1a7
+2026-07-20-error-cause-chain-diagnostics.md: 700c36c45ae8c939b6d9161ab90ab5dfe2c92686
+2026-07-20-error-cause-chain-diagnostics.zh.md: b358ec606b7c92641f3e6138fe23d832431bd5ce

.agents/notes/implemented/bug-fix/2026-07-20-error-cause-chain-diagnostics.md

@@ -15,7 +15,7 @@ A TUI run against an unreachable DeepSeek endpoint failed with the single notice
 
 - `dsh-llm` exports `errorChain(value)`: renders a thrown value with its full `cause` chain (`outer: inner: …`) and AggregateError members (`msg [m1; m2]`), with circular-cause and hostile-coercion containment. It is a diagnostic-surface renderer only; routing stays on `HarnessError.code`.
 - The DeepSeek adapter wraps a pre-response transport failure in `LlmError('TRANSPORT')` naming the configured `baseURL` and chaining the original rejection as `cause`. An aborted request becomes `LlmError('ABORTED')`; because the turn signal is already aborted, the loop still classifies the turn as cancellation rather than recovery.
-- Every diagnostic seam renders through `errorChain` instead of `error.message`/`String(error)`: the agent-loop's durable `turn/end` error message (`errorData`), its logger warnings, the TUI's `agent/error` notice and startup-failure line, and `dsh-stdio`'s startup-failure log lines. The per-package `renderThrown` copies in `dsh-agent-loop`, `dsh-stdio`, and `dsh-tui` are deleted in favor of the one shared renderer.
+- Every diagnostic seam renders through `errorChain` instead of `error.message`/`String(error)`: the agent-loop's durable `turn/end` error message (`errorData`), its logger warnings, the TUI's `agent/error` notice and startup-failure line, and `dsh-stdio`'s startup-failure log lines. The live `agent/error` event and `IdleReason` preserve the thrown value as `unknown`; each diagnostic consumer renders it instead of the loop wrapping it into another error. The per-package `renderThrown` copies in `dsh-agent-loop`, `dsh-stdio`, and `dsh-tui` are deleted in favor of the one shared renderer.
 - `dsh-stdio` renders failure `turn/end` reasons: `[turn failed <code>] <message>`, `[turn aborted] <reason>`, `[turn rejected] <reason>`, `[turn interrupted by a previous process exit]`, and the output-token-limit notice. Unknown merge-extended kinds fall through as ordinary turn ends.
 
 `errorChain` lives in `dsh-llm` beside `HarnessError` for the same reason the base class does: it is the leaf package every consumer already imports, so sharing costs no new dependency edge.

.agents/notes/implemented/bug-fix/2026-07-20-error-cause-chain-diagnostics.zh.md

@@ -15,7 +15,7 @@ TUI 连接不可达的 DeepSeek 端点时，失败只显示一条 `fetch failed`
 
 - `dsh-llm` 导出 `errorChain(value)`：渲染抛出值及其完整 `cause` 链（`outer: inner: …`）与 AggregateError 成员（`msg [m1; m2]`），并容错循环 cause 和恶意强制转换。它只是诊断表面的渲染器；路由仍然基于 `HarnessError.code`。
 - DeepSeek 适配器把拿到响应之前的传输失败包装成 `LlmError('TRANSPORT')`，写明配置的 `baseURL` 并把原始拒绝值链为 `cause`。被中止的请求变为 `LlmError('ABORTED')`；由于轮次信号已处于中止状态，循环仍将该轮次归类为取消而非恢复。
-- 每个诊断接缝改用 `errorChain` 而非 `error.message`/`String(error)`：agent-loop 的持久化 `turn/end` 错误消息（`errorData`）、其日志警告、TUI 的 `agent/error` 通知与启动失败行、以及 `dsh-stdio` 的启动失败日志行。`dsh-agent-loop`、`dsh-stdio`、`dsh-tui` 里各自的 `renderThrown` 副本被删除，统一使用这一个共享渲染器。
+- 每个诊断接缝改用 `errorChain` 而非 `error.message`/`String(error)`：agent-loop 的持久化 `turn/end` 错误消息（`errorData`）、其日志警告、TUI 的 `agent/error` 通知与启动失败行、以及 `dsh-stdio` 的启动失败日志行。实时 `agent/error` 事件与 `IdleReason` 以 `unknown` 原样保留抛出值；各诊断消费者自行渲染，而不是由循环把它包装成另一个错误。`dsh-agent-loop`、`dsh-stdio`、`dsh-tui` 里各自的 `renderThrown` 副本被删除，统一使用这一个共享渲染器。
 - `dsh-stdio` 渲染失败的 `turn/end` reason：`[turn failed <code>] <message>`、`[turn aborted] <reason>`、`[turn rejected] <reason>`、`[turn interrupted by a previous process exit]` 以及输出 token 上限通知。未知的 merge 扩展 kind 按普通 turn 结束处理。
 
 `errorChain` 与 `HarnessError` 一样放在 `dsh-llm` 里，理由相同：它是每个消费者都已导入的叶子包，共享不增加新的依赖边。