test(web): navigation & panes scenarios over one rich seeded session

One two-turn seed (turn 1: bash + two parallel reads in a single assistant
message; turn 2: a markdown-heavy reply) rendered cold through the
seeded-history pattern — zero model calls — serving four surfaces:

- sidebar search: client-side title filter; asserted only after the durable
  title lands with the attach baseline (a cold SessionSummary carries no
  title — search matches the displayTitle the user sees). Negative query
  empties the tree, positive narrows to the match + its force-expanded
  group, clear restores.
- Trajectory tab: turn sections, the step group's tool mix ('bash read×2'),
  and a view-area aria golden.
- Waterfall tab: span stats header + one lane per span. The P-I fold counts
  a turn-0 prologue span (only assistant/steering nodes carry a turn
  number) — pinned as-is; real spans are P-III per the view's ledger.
- details column: the bash toolview row routes click to openDetails;
  open/closed is asserted on the frame's data-details-collapsed attribute
  because close collapses the grid column to width 0 without unmounting
  the subtree (hidden, not absent, is the contract).

Agent Note scenario list extended in both languages; pairing re-recorded.

.agents/notes/implemented/testing/2026-07-24-web-gui-browser-e2e-lane.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
-2026-07-24-web-gui-browser-e2e-lane.md: 78a01652ef35f371c35c059033cd28f29f5bf94e
-2026-07-24-web-gui-browser-e2e-lane.zh.md: b5fb29c63ab10352d50ef6ba9ce7b65e92989387
+2026-07-24-web-gui-browser-e2e-lane.md: f97bcfa77e3e6949945197cfe33abd7e1eec8008
+2026-07-24-web-gui-browser-e2e-lane.zh.md: 3ec27956dd3c2ed985600d9e24f90155f99dc932

.agents/notes/implemented/testing/2026-07-24-web-gui-browser-e2e-lane.md

@@ -47,6 +47,7 @@ The typecheck plane split is structural: the three files that boot the host spin
 3. **`live-interactions`** — one tool-free recorded turn serves three replay-only scenarios through override sidecars whose CONTENT is authored in the spec and minted as a per-run file in a spec-owned temp dir (the derived success entry for the retry append is re-derived from the fixture via `deriveReplayScript`, never copied into a committed sidecar). Cancel: a `{ patches }` `hang` with a `readyFile` marker — the marker's existence proves the stream is parked mid-turn before the test clicks Stop, making mid-stream cancellation deterministic by construction (`turn/end` reason `aborted`, composer re-enabled). AUTH error: a pre-chunk `throw` outside llm-retry's retryable set (`turn/end` reason `error`, zero `llm/retry` events, composer recovers). SERVER retry: `throw` at call 0 + the fixture's own success appended at 1, proving llm-retry end-to-end in the browser via the durable `llm/retry` record (`request/header` logs only on change, so attempt count is invisible there).
 4. **`question-composer`** — the shipped composition's resident `ask_user_question` takeover: a recorded turn blocks mid-step on the real userInteraction seam, the composer (`[data-question-key]`) renders in the browser, the test answers through it (the ONE sanctioned place a drive step reacts to model content: the turn cannot complete without the answer, in record and replay alike), and the tool result carries the chosen label. Golden: the composer's stable waiting state.
 5. **`steering`** — mid-turn steer while the question composer blocks the step (the deterministic mid-turn window; no timing dependence). The composer locks while running, so the steer POSTs `session.prompt` `mode:'steer'` from the page over the same same-origin `/api` wire the client uses (`TODO(web-steer-composer)`: drive a composer gesture once one exists); everything downstream is product — gateway → `Agent.steer` → step-boundary drain → durable `steering/message` → SSE → badged interjection bubble. Record-mode fixture honesty: the recording is rejected unless the live model's final reply obeys an instruction only the steering message carries.
+6. **`navigation-panes`** — one rich two-turn seed (turn 1: bash + two parallel reads in one assistant message; turn 2: a markdown-heavy reply) rendered cold through the seeded-history pattern (zero model calls), serving four surfaces: sidebar search (client-side title filter — asserted only after the durable title lands with the attach baseline, because a cold `SessionSummary` carries no title and search matches the `displayTitle` the user sees; negative query empties the tree, positive narrows, clear restores), the Trajectory tab (turn sections + the step group's tool mix plus the view-area aria golden), the Waterfall tab (span stats + one lane per span — the P-I fold counts a turn-0 prologue span because only assistant/steering nodes carry a turn number, pinned as-is), and the details column (the bash toolview row routes click to openDetails; open/closed is asserted on the frame's `data-details-collapsed` attribute because close collapses the grid column to width 0 without unmounting the subtree).
 
 ### CI stance
 

.agents/notes/implemented/testing/2026-07-24-web-gui-browser-e2e-lane.zh.md

@@ -47,6 +47,7 @@ Web GUI 以一条真实组装链交付——chromium 页面 → client 插件 bu
 3. **`live-interactions`**——一段不含工具调用的已录轮次经覆写 sidecar 承载三个仅回放的场景：sidecar 的内容本身写在 spec 里，每次运行时在 spec 自有的临时目录中生成文件（重试追加所用的派生成功条目经 `deriveReplayScript` 从 fixture 重新派生，绝不复制进已提交的 sidecar）。取消：一个带 `readyFile` 标记的 `{ patches }` `hang`——标记文件的存在证明流在测试点击 Stop 之前已停驻在轮次中途，使流中取消按构造即确定（`turn/end` 原因为 `aborted`，输入框重新启用）。AUTH 错误：一次落在 llm-retry 可重试集合之外的分片前 `throw`（`turn/end` 原因为 `error`，零条 `llm/retry` 事件，输入框恢复可用）。SERVER 重试：第 0 次调用 `throw` + 在第 1 次调用处追加 fixture 自身的成功条目，凭持久的 `llm/retry` 记录在浏览器中端到端证明 llm-retry（`request/header` 仅在变化时记录，因此尝试次数在那里不可见）。
 4. **`question-composer`**——已交付组合中常驻的 `ask_user_question` 接管：一段已录轮次在真实的 userInteraction seam 上阻塞于步骤中途，提问输入框（`[data-question-key]`）在浏览器中渲染，测试经它作答（这是驱动步骤对模型内容作出反应的唯一获准之处：没有这个回答，轮次无法完成，record 与 replay 皆然），工具结果携带所选的 label。预期输出：提问输入框稳定的等待态。
 5. **`steering`**——在提问输入框阻塞该步骤时做轮次中途 steering（中途引导），此即确定性的轮次中途窗口，不依赖任何时序。输入框在运行期间锁定，因此这一 steer 由页面经客户端所用的同一条同源 `/api` wire POST `session.prompt` `mode:'steer'`（`TODO(web-steer-composer)`：待有输入框手势后改为驱动它）；下游的一切都是产品路径——gateway → `Agent.steer` → 步骤边界排空 → 持久的 `steering/message` → SSE → 带徽标的插话气泡。record 模式的 fixture 诚实性：除非真实模型的最终回复遵循了一条只有 steering 消息才携带的指令，否则该次录制被拒绝。
+6. **`navigation-panes`**——一份内容丰富的双轮次种子（轮次 1：同一条 assistant 消息内的 bash + 两次并行 read；轮次 2：一段 markdown 密集的回复）经 seeded-history 模式冷渲染（零模型调用），承载四个表面：侧栏搜索（客户端标题过滤；仅在持久的标题随 attach 基线一同到达后才断言，因为冷的 `SessionSummary` 不携带标题，而搜索匹配的是用户所见的 `displayTitle`；反例查询清空整棵树，正例查询收窄，清除后复原）、Trajectory 标签页（轮次分节 + 步骤组的工具构成，外加视图区 aria 预期输出）、Waterfall 标签页（span 统计 + 每个 span 一条泳道；只有 assistant/steering 节点携带轮次编号，因此 P-I 折叠会将一个轮次 0 的序幕 span 计入，按原样钉住）与详情列（bash 工具视图行把点击路由到 openDetails；打开/关闭状态断言在 frame 的 `data-details-collapsed` 属性上，因为关闭把网格列收缩到宽度 0 而不卸载子树）。
 
 ### CI 立场