fix(gui): tail history page carries the full-log todo projection

The client's todos projection derived only from the paged display window,
so reopening a session whose last todo/write preceded the tail page showed
an empty plan until the user paged back — session-level state cannot be
reconstructed from an arbitrary window. The host owns the full log, so the
tail history response now attaches todos (latest todo/write backscan, the
same posture as the view pairing); installWindow seeds it, window rebuilds
preserve it, and any in-window or live write keeps overwriting it. The
fixture mirrors the host; docs and both Agent Notes record the mechanism.

.agents/notes/implemented/feature/2026-06-29-todo-write-tool.md

@@ -18,7 +18,7 @@ The model sends the ENTIRE list every call; the new list replaces the old (last-
 
 ### State on the session log, not a service
 
-The list is appended as a `todo/write` event carrying the full `{ todos }` snapshot. The harness is event-sourced — the LLM history, tool calls, and turn structure all live on the log — so the todo list lives there too. This buys durability, replay, and `session/load` reconstruction for free: a reopened session re-derives the current list (the last `todo/write`) and the ACP bridge re-emits the `plan` on load, with no separate persistence backend, no in-memory service to rehydrate, and no extra wiring. An in-memory `ctx.todos` service would have had to reinvent all of that. (Full-log consumers get this reconstruction outright; the web client's paged window currently sees only the tail page — the gap and its fix directions are recorded in the [web todo display note](2026-07-23-web-todo-display.md).)
+The list is appended as a `todo/write` event carrying the full `{ todos }` snapshot. The harness is event-sourced — the LLM history, tool calls, and turn structure all live on the log — so the todo list lives there too. This buys durability, replay, and `session/load` reconstruction for free: a reopened session re-derives the current list (the last `todo/write`) and the ACP bridge re-emits the `plan` on load, with no separate persistence backend, no in-memory service to rehydrate, and no extra wiring. An in-memory `ctx.todos` service would have had to reinvent all of that. (Full-log consumers get this reconstruction outright; the web client's paged window gets it from the tail history page's host-computed projection — see the [web todo display note](2026-07-23-web-todo-display.md).)
 
 ### NOT a surface event
 

.agents/notes/implemented/feature/2026-07-23-web-todo-display.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
-2026-07-23-web-todo-display.md: 003ab29546e8098331496641a28d095a1dd95fed
-2026-07-23-web-todo-display.zh.md: 200fd1d44dca7c5bcaa4f47ac31e26cb1f0f8d3d
+2026-07-23-web-todo-display.md: a5b45f288518cd53594aea724fb8eba532a1142d
+2026-07-23-web-todo-display.zh.md: d960a5ab402d9f1c53ddecc7838b19da0743ef3b

.agents/notes/implemented/feature/2026-07-23-web-todo-display.md

@@ -32,4 +32,4 @@ The dedicated `todo_write` chat row registers through the named `ctx.toolviews`
 
 ## Consequences
 
-Replay correctness is owned by one code path: any future change to window rebuild keeps todos consistent for free, and the fixture (fx-alpha turn 63) plus `scripts/verify-todo-display.mjs` pin the full chain (panel visibility, row summary, details linkage, collapse, dark theme) in a real chromium. `todos` is a required `ConversationSnapshot` field, so scripted fakes in specs must carry it. The ACP bridge's todo → `plan` mapping and the TUI panel are untouched; the web surfaces render the same event with no new wire vocabulary. Known gap: the projection is window-scoped — reopening a session whose last `todo/write` precedes the tail history page shows an empty plan until the user pages back to it; restoring the tool note's cold-load reconstruction promise needs the current projection independent of the display window (host-attached on the history response, or a dedicated read).
+Replay correctness is owned by one code path: any future change to window rebuild keeps todos consistent for free, and the fixture (fx-alpha turn 63) plus `scripts/verify-todo-display.mjs` pin the full chain (panel visibility, row summary, details linkage, collapse, dark theme) in a real chromium. `todos` is a required `ConversationSnapshot` field, so scripted fakes in specs must carry it. The ACP bridge's todo → `plan` mapping and the TUI panel are untouched; the web surfaces render the same event with no new wire vocabulary. Cold-load reconstruction is host-backed: the tail history page carries `todos` — the full-log latest `todo/write`, computed independently of the page window (the same backscan posture the view pairing uses) — so a reopened session restores the plan even when the last write precedes the window; the seeded value is preserved across window rebuilds and overwritten by any later write.

.agents/notes/implemented/feature/2026-07-23-web-todo-display.zh.md

@@ -32,4 +32,4 @@ Status: implemented
 
 ## Consequences
 
-回放正确性由一条代码路径掌管：未来对窗口重建的任何改动都免费保持 todos 一致；fx-alpha 第 63 轮的 fixture（测试前置数据）加 `scripts/verify-todo-display.mjs` 在真实 chromium 里钉住整条链（面板可见性、行摘要、详情联动、折叠、深色主题）。`todos` 是 `ConversationSnapshot` 的必填字段，所以 spec 里脚本化的 fake 必须带上它。ACP 桥接的 todo → `plan` 映射与 TUI 面板均未受改动；Web 各面渲染同一个事件，不引入任何新的协议词汇。已知缺口：该投影以窗口为界——重新打开一个最后一次 `todo/write` 落在尾页之前的会话时，计划面板为空，直到用户翻页翻到它；要兑现工具 Note 里冷加载重建的承诺，需要一份独立于显示窗口的当前投影（history 响应由 host 附带，或提供专门的读取口）。
+回放正确性由一条代码路径掌管：未来对窗口重建的任何改动都免费保持 todos 一致；fx-alpha 第 63 轮的 fixture（测试前置数据）加 `scripts/verify-todo-display.mjs` 在真实 chromium 里钉住整条链（面板可见性、行摘要、详情联动、折叠、深色主题）。`todos` 是 `ConversationSnapshot` 的必填字段，所以 spec 里脚本化的 fake 必须带上它。ACP 桥接的 todo → `plan` 映射与 TUI 面板均未受改动；Web 各面渲染同一个事件，不引入任何新的协议词汇。冷加载重建由 host 兜底：history 尾页附带 `todos`——全量 log 上最新一次 `todo/write` 的投影，独立于分页窗口计算（与 view 配对同一种 backscan 姿势）——因此重开会话时即使最后一次写入落在窗口之前，计划也照常恢复；播种值跨窗口重建保留，之后的任何写入照常覆盖。