refactor(client): archivedSessionIds public face becomes a plain array

Public snapshot state stays in the store engine's plain-data vocabulary
(immer drafts reject Sets without the MapSet plugin, which stays off):
manager/service/contract carry readonly SessionId[] in Host order, and
the tree derivations build their own transient Set — the
expandedProjects pattern. Membership-unchanged installs still keep the
array reference for Object.is short-circuits.

.agents/notes/implemented/feature/2026-07-31-session-archive-global-set.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/feature/2026-07-31-session-archive-global-set.md
-2026-07-31-session-archive-global-set.md: b318be9985b197171a046a5abeab3c93b879c710
-2026-07-31-session-archive-global-set.zh.md: 8e3157f4c55c54c3fdd3132034b28567b9b25013
+2026-07-31-session-archive-global-set.md: fab99a405a6f8264c36453473327e32905bac9c8
+2026-07-31-session-archive-global-set.zh.md: e33f3b5272a6d8fc90cfad247ba21d4d10afb045

.agents/notes/implemented/feature/2026-07-31-session-archive-global-set.md

@@ -15,7 +15,7 @@ The session row menu in the sidebar workspace browser carried a purely visual "D
 - Storage: `archivedSessionIds: z.array(sessionId).default([])`, domain version stays 2 — a purely additive field; pre-field media parse to an empty set through the schema default, no migration code. An archived session keeps its `sessionIds` slot (a future unarchive restores its position), so the set never touches the one-owner accounting invariant.
 - Registry: `ctx.workspace.archiveSession(id)` rides `enqueueOperation`, serialized with create/delete; a session neither live nor persisted throws `WorkspaceUnknownSessionError`; an already archived id neither writes nor emits. The `archivedSessionIds` getter exposes the read-only set.
 - RPC: `workspace.archiveSession({sessionId}) → {archivedSessionIds}` (answers the full updated set); the `workspace.list` response carries the set as the reconnect baseline; a new host frame `host/archived-sessions-changed` pushes the full snapshot after every durable change (same posture as `host/workspace-changed`, emitted from the `domain/changed` global-put branch by set comparison). Unknown sessions reuse the `session-not-found` error code.
-- Client runtime: `WorkspaceListState.archivedSessionIds` (a `ReadonlySet`, reference replaced only on membership change); the list baseline, the unary echo, and the changed frame each install the complete set. the projection sweep clears the current selection whenever it lands in the archive set, returning to the New Session view (user decision: archiving the open session sends the main view back to the hero) — one rule covering the local unary echo, another tab's changed frame, and a reconnect baseline restoring a selection archived while this client was away; a frame or echo landing during an in-flight `workspace.list` also shields the newer set from the stale baseline.
+- Client runtime: `WorkspaceListState.archivedSessionIds` (a `readonly SessionId[]` in Host order, reference replaced only on membership change — public snapshot state stays in the store engine's plain-data vocabulary since immer drafts reject Sets without the MapSet plugin; membership lookups build a transient Set in the derivation, the expandedProjects pattern); the list baseline, the unary echo, and the changed frame each install the complete set. the projection sweep clears the current selection whenever it lands in the archive set, returning to the New Session view (user decision: archiving the open session sends the main view back to the hero) — one rule covering the local unary echo, another tab's changed frame, and a reconnect baseline restoring a selection archived while this client was away; a frame or echo landing during an in-flight `workspace.list` also shields the newer set from the stale baseline.
 - UI: the `delete` menu row (visual-only) becomes `archive` (label "Archive session", non-danger styling, no confirmation dialog — a non-destructive action whose worst misfire is list hiding); filtering is one extra arm in `tree.ts`'s `sessionVisible` predicate, with `deriveGroups`/`deriveFlat` taking an `archived` set parameter so all four surfaces (group loop, stray bucket, search, flat) share one source.
 
 ## Alternatives considered

.agents/notes/implemented/feature/2026-07-31-session-archive-global-set.zh.md

@@ -15,7 +15,7 @@ Sidebar workspace 浏览区的 session 行菜单里，「Delete session」一直
 - 存储：`archivedSessionIds: z.array(sessionId).default([])`，domain version 保持 2——纯增量字段，旧介质经 schema default 解析为空集合，无迁移代码。被归档的 session 保留其 `sessionIds` 席位（未来取消归档恢复原位置），因此与「一个 session 只被一个 workspace 记账」不变式零纠缠。
 - Registry：`ctx.workspace.archiveSession(id)` 走 `enqueueOperation` 与 create/delete 串行；未知 session（实时与持久化都查不到）抛 `WorkspaceUnknownSessionError`；已归档 id 不写盘不发事件。`archivedSessionIds` getter 暴露只读集合。
 - RPC：`workspace.archiveSession({sessionId}) → {archivedSessionIds}`（应答完整更新后集合）；`workspace.list` 响应携带集合作为重连基线；新 host 帧 `host/archived-sessions-changed` 在每次持久变更后推完整快照（与 `host/workspace-changed` 同姿态，从 `domain/changed` 的 global put 分支比对推帧）。未知 session 复用错误码 `session-not-found`。
-- client runtime：`WorkspaceListState.archivedSessionIds`（`ReadonlySet`，成员不变不换引用）；list 基线、unary 回声、changed 帧三路都整体替换安装。投影层在当前 selection 落入归档集合时统一清空回 New Session 视图（用户拍板：归档当前打开的 session 主视图回 hero）——一条规则同时覆盖本地 unary 回声、其他标签页的 changed 帧、以及重连基线恢复出一个离线期间被归档的 selection；帧/回声落在 in-flight `workspace.list` 期间时还会屏蔽旧基线对新集合的回滚。
+- client runtime：`WorkspaceListState.archivedSessionIds`（按 Host 顺序的 `readonly SessionId[]`，成员不变不换引用——公有快照状态保持 store 引擎的纯数据词汇：immer draft 不开 MapSet 插件就不接受 Set；membership 查询在派生函数内自建临时 Set，与 expandedProjects 同款）；list 基线、unary 回声、changed 帧三路都整体替换安装。投影层在当前 selection 落入归档集合时统一清空回 New Session 视图（用户拍板：归档当前打开的 session 主视图回 hero）——一条规则同时覆盖本地 unary 回声、其他标签页的 changed 帧、以及重连基线恢复出一个离线期间被归档的 selection；帧/回声落在 in-flight `workspace.list` 期间时还会屏蔽旧基线对新集合的回滚。
 - UI：菜单项 `delete`（visual-only）改为 `archive`（label「Archive session」，非 danger 样式，无确认对话框——非破坏性操作，误触后果只是列表隐藏）；过滤实现为 `tree.ts` 的 `sessionVisible` 判据加一档，`deriveGroups`/`deriveFlat` 增加 `archived` 集合入参，四个视图（分组循环、stray 兜底、搜索、平铺）同源生效。
 
 ## 已考虑的替代方案