feat(ui-workspace): reorder ungrouped sessions

.agents/notes/implemented/feature/2026-08-11-workspace-sidebar-order-and-folding.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/2026-08-11-workspace-sidebar-order-and-folding.md
-2026-08-11-workspace-sidebar-order-and-folding.md: 78d8399b2f5cb1f8f33ffe3ba89ff27944ae8e63
-2026-08-11-workspace-sidebar-order-and-folding.zh.md: 87449ddd7265a6bcb11d7a2e4ffc8ac2a5c9257c
+2026-08-11-workspace-sidebar-order-and-folding.md: ad011d313dfea3e0c1992946230e3d9577646520
+2026-08-11-workspace-sidebar-order-and-folding.zh.md: a3391113869e4c9002ee0a803bb40fc11c523f68

.agents/notes/implemented/feature/2026-08-11-workspace-sidebar-order-and-folding.md

@@ -20,9 +20,9 @@ The client installs a Workspace drag optimistically. Request and frame generatio
 
 ### Session folding and view order
 
-Each Workspace persists one browser-local open state: closed means zero Session rows and open means up to five. When more Sessions exist, **Show more** reveals the remainder only for the current mount; closing the whole Workspace clears this transient expansion, so reopening returns to five. The current Session's group opens automatically only when the user has not already stored an explicit state for that Workspace. After a ready Workspace baseline changes, the browser removes expansion, order, and observed-timestamp records for ids absent from that baseline while retaining the Ungrouped expansion key.
+Each Workspace persists one browser-local open state: closed means zero Session rows and open means up to five. When more Sessions exist, **Show more** reveals the remainder only for the current mount; closing the whole Workspace clears this transient expansion, so reopening returns to five. The current Session's group opens automatically only when the user has not already stored an explicit state for that Workspace. After a ready Workspace baseline changes, the browser removes expansion, order, and observed-timestamp records for ids absent from that baseline while retaining the Ungrouped key for expansion, order, and observed timestamps.
 
-The combined view menu offers **Manual** and **Last updated** over one browser-local, persisted per-Workspace order initialized from `WorkspaceView.sessionIds`. Entering Last updated performs one complete recency sort; a later user prompt or steer promotes that Session once, and dragging may edit the resulting order. Returning to Manual preserves the current order and only disables later activity promotion. Manual-mode drags also write the Host Session account, while activity promotion remains a browser-local presentation choice. The flat list uses recency because it has no single Workspace account for durable Session drag.
+The combined view menu offers **Manual** and **Last updated** over one browser-local persisted order per group. A real Workspace initializes from `WorkspaceView.sessionIds`; Ungrouped initializes from recency and has no Host Session account. Entering Last updated performs one complete recency sort; a later user prompt or steer promotes that Session once, and dragging may edit the resulting order. Returning to Manual preserves the current order and only disables later activity promotion. Manual-mode drags for a real Workspace also write the Host Session account, while Ungrouped drags and activity promotion remain browser-local. The flat list uses recency because it has no single group account for Session drag.
 
 ### Drag and compact chrome
 
@@ -46,11 +46,11 @@ Search is a header action while collapsed and expands across the title and trail
 
 ## Consequences
 
-- Workspace order is durable and shared through the Host, while grouping, open state, the shared Session view order, and query state remain browser-local presentation preferences.
+- Workspace order is durable and shared through the Host, while grouping, open state, per-group Session view order, and query state remain browser-local presentation preferences. Ungrouped supports the same drag and promotion rules, but its order is browser-local because no Workspace owns those Sessions.
 - Last updated performs a complete recency sort on entry, then preserves manual adjustments until a user prompt or steer advances one Session and moves it to the front. Returning to Manual preserves every current position.
 - Opening a Workspace never shows more than five Sessions without an explicit **Show more** gesture, and closing it resets only that transient gesture.
 - The Host Session account retains the manual-order meaning established by [Session List Browsing and Manual Workspace Order](2026-07-25-session-list-browsing-and-manual-order.md).
 
 ## Testing
 
-Domain and Host tests cover durable Workspace moves, no-op and invalid anchors, restart recovery, full-order RPC responses, order frames, and one Workspace snapshot per Host-stream baseline. Runtime tests cover optimistic order, frame/response precedence, overlapping rejection rollback to Host-confirmed order, reconnect baselines, and New Session target priority. UI tests cover five-row folding, transient expansion reset, pruning persisted state after Workspace removal, order-preserving mode switches, one-time recent-update promotion, selected view indicators, expanded-section Workspace hit testing, an unclipped first insertion boundary, outside-list Workspace and Session drops, search collapse rules, and compact CSS dimensions.
+Domain and Host tests cover durable Workspace moves, no-op and invalid anchors, restart recovery, full-order RPC responses, order frames, and one Workspace snapshot per Host-stream baseline. Runtime tests cover optimistic order, frame/response precedence, overlapping rejection rollback to Host-confirmed order, reconnect baselines, and New Session target priority. UI tests cover five-row folding, transient expansion reset, pruning persisted state after Workspace removal, order-preserving mode switches, one-time recent-update promotion, browser-local Ungrouped drag persistence in both modes, selected view indicators, expanded-section Workspace hit testing, an unclipped first insertion boundary, outside-list Workspace and Session drops, search collapse rules, and compact CSS dimensions.

.agents/notes/implemented/feature/2026-08-11-workspace-sidebar-order-and-folding.zh.md

@@ -20,9 +20,9 @@ Workspace 注册表持有持久 `workspaceIds` 顺序，并提供采用 DOM `ins
 
 ### Session 折叠与视图顺序
 
-每个 Workspace 持久化一项浏览器本地打开状态：关闭表示零条 Session 行，打开表示最多五条。存在更多 Session 时，**展开其余**只在当前挂载期间显示剩余项；关闭整个 Workspace 会清除此临时展开，因此重新打开时恢复为五条。只有在用户尚未为该 Workspace 存储明确状态时，当前 Session 所在分组才会自动打开。就绪的 Workspace 基线发生变化后，浏览器会移除基线中不存在 id 的展开状态、顺序和已观察时间戳记录，同时保留 Ungrouped 的展开键。
+每个 Workspace 持久化一项浏览器本地打开状态：关闭表示零条 Session 行，打开表示最多五条。存在更多 Session 时，**展开其余**只在当前挂载期间显示剩余项；关闭整个 Workspace 会清除此临时展开，因此重新打开时恢复为五条。只有在用户尚未为该 Workspace 存储明确状态时，当前 Session 所在分组才会自动打开。就绪的 Workspace 基线发生变化后，浏览器会移除基线中不存在 id 的展开状态、顺序和已观察时间戳记录，同时为 Ungrouped 保留展开、顺序和已观察时间戳所用的键。
 
-组合视图菜单在同一份按 Workspace 持久于浏览器本地、由 `WorkspaceView.sessionIds` 初始化的顺序上提供**手动排序**和**最近更新**。进入最近更新时会执行一次完整的时间排序；后续 user prompt 或 steer 会将对应 Session 置顶一次，拖拽仍可编辑所得顺序。返回手动排序会保留当前顺序，只停用后续活动置顶。手动模式下的拖拽还会写入 Host Session 记账，而活动置顶仍属于浏览器本地呈现选择。平铺列表没有可承载持久 Session 拖拽的单一 Workspace 记账，因此使用最近更新顺序。
+组合视图菜单在每个分组各自的一份浏览器本地持久顺序上提供**手动排序**和**最近更新**。真实 Workspace 从 `WorkspaceView.sessionIds` 初始化；Ungrouped 从最近更新时间顺序初始化，且没有 Host Session 记账。进入最近更新时会执行一次完整的时间排序；后续 user prompt 或 steer 会将对应 Session 置顶一次，拖拽仍可编辑所得顺序。返回手动排序会保留当前顺序，只停用后续活动置顶。真实 Workspace 在手动模式下的拖拽还会写入 Host Session 记账，而 Ungrouped 拖拽和活动置顶保留在浏览器本地。平铺列表没有可承载 Session 拖拽的单一分组记账，因此使用最近更新顺序。
 
 ### 拖拽与紧凑界面
 
@@ -46,11 +46,11 @@ Workspace 命中测试使用完整渲染分组区段，包括可见 Session 行
 
 ## 后果
 
-- Workspace 顺序通过 Host 持久并共享；分组方式、打开状态、共享 Session 视图顺序和查询状态仍是浏览器本地呈现偏好。
+- Workspace 顺序通过 Host 持久并共享；分组方式、打开状态、每个分组的 Session 视图顺序和查询状态仍是浏览器本地呈现偏好。Ungrouped 支持相同的拖拽与置顶规则，但因没有 Workspace 持有其中的 Session，其顺序只保存在浏览器本地。
 - 最近更新模式会在进入时执行完整时间排序，随后保持手动调整，直到 user prompt 或 steer 推进某条 Session 并将其置顶。返回手动排序会保留所有当前位置。
 - 未执行明确的**展开其余**手势时，打开 Workspace 最多显示五条 Session；关闭分组只重置这项临时手势。
 - Host Session 记账继续采用[会话列表浏览与 Workspace 手动排序](2026-07-25-session-list-browsing-and-manual-order.md)确立的手动顺序含义。
 
 ## 测试
 
-领域与 Host 测试覆盖持久 Workspace 移动、无操作与无效锚点、重启恢复、完整顺序 RPC 响应、顺序帧以及每条 Host stream 基线只读取一份 Workspace 快照。运行时测试覆盖乐观顺序、帧／响应优先级、重叠拒绝后恢复 Host 已确认顺序、重连基线以及 New Session 目标优先级。UI 测试覆盖五行折叠、临时展开重置、Workspace 移除后清理持久状态、保持顺序的模式切换、一次性最近更新置顶、当前视图标记、展开区段的 Workspace 命中、未裁切的第一条插入边界、列表外 Workspace 与 Session 松手、搜索收起规则和紧凑 CSS 尺寸。
+领域与 Host 测试覆盖持久 Workspace 移动、无操作与无效锚点、重启恢复、完整顺序 RPC 响应、顺序帧以及每条 Host stream 基线只读取一份 Workspace 快照。运行时测试覆盖乐观顺序、帧／响应优先级、重叠拒绝后恢复 Host 已确认顺序、重连基线以及 New Session 目标优先级。UI 测试覆盖五行折叠、临时展开重置、Workspace 移除后清理持久状态、保持顺序的模式切换、一次性最近更新置顶、两种模式下的浏览器本地 Ungrouped 拖拽持久化、当前视图标记、展开区段的 Workspace 命中、未裁切的第一条插入边界、列表外 Workspace 与 Session 松手、搜索收起规则和紧凑 CSS 尺寸。

packages/client/ui-workspace/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/client/ui-workspace/README.md
-README.md: 3308044abe32ba36d45b02ddacba93772265d315
-README.zh.md: 38ccb89e0a1fa03ce2d2bab08e7605d8c60f2472
+README.md: 98edb22dd173d8d6f119a4494baeb7e16cec98f6
+README.zh.md: 4f0a8f1950889bb9247899ea14d062bd0ee07c4d

packages/client/ui-workspace/README.md

@@ -4,7 +4,7 @@ English | [中文](README.zh.md)
 
 Shared Workspace browser and picker plugin. `WorkspaceBrowser` fills the sidebar's `sidebar.workspaces` slot, while `WorkspacePicker` fills the page-local Session Intent hero's `conversation.hero.workspace` slot; both surfaces use the same Workspace menu and add flow.
 
-The browser renders grouped or flat Session rows from the global runtime hooks and owns Workspace add/rename/reorder plus in-Workspace Session reorder. A Workspace remembers whether it is closed or showing Sessions; an open Workspace shows five Sessions by default, offers a transient **Show more** control for the remainder, and returns to five after the whole Workspace is closed and reopened. Once the Workspace list baseline is ready, browser-persisted expansion and Session-order records retain only current Workspace ids plus Ungrouped. View options combine grouping with one browser-persisted Session order: entering **Last updated** performs a complete recency sort and later user prompts or steers promote their Session once, while entering **Manual** preserves every current position and disables later promotion. Dragging edits the current order in either mode; Manual-mode drags also update the Host Workspace account. Workspace drag order is Host-durable in either Session order mode.
+The browser renders grouped or flat Session rows from the global runtime hooks and owns Workspace add/rename/reorder plus grouped Session reorder. A Workspace remembers whether it is closed or showing Sessions; an open Workspace shows five Sessions by default, offers a transient **Show more** control for the remainder, and returns to five after the whole Workspace is closed and reopened. Once the Workspace list baseline is ready, browser-persisted expansion and Session-order records retain only current Workspace ids plus Ungrouped. View options combine grouping with one browser-persisted Session order per group: real Workspaces initialize from `WorkspaceView.sessionIds`, while Ungrouped initializes from recency. Entering **Last updated** performs a complete recency sort and later user prompts or steers promote their Session once, while entering **Manual** preserves every current position and disables later promotion. Dragging edits the current order in either mode; Manual-mode drags for real Workspaces also update the Host Session account, while Ungrouped order remains browser-local because no Workspace owns those Sessions. Workspace drag order is Host-durable in either Session order mode.
 
 Collapsed search is one header action beside the view and add actions. Activating it expands the field across the header; an outside click collapses only a query that is empty after trimming, while the clear control always resets and collapses it. A non-blank search query replaces either browsing mode with one flat result list: case-insensitive title and Workspace substring matches appear immediately, while a 250 ms debounced Host request adds ranked current-conversation content matches and snippets. The English search input and its defensive request path remove NUL, cap the query at the wire schema's 500 UTF-16 code units without splitting a surrogate pair, and preserve the existing debounce and cancellation behavior. Each new query aborts the preceding request; a failed content search leaves metadata matches visible with a warning. The list is capped at 20, asks the user to narrow broader queries, and opens the selected Session without clearing the query or jumping to a specific event.
 

packages/client/ui-workspace/README.zh.md

@@ -4,7 +4,7 @@
 
 共享 Workspace 浏览器与选择器插件。`WorkspaceBrowser` 填充侧边栏的 `sidebar.workspaces` slot，`WorkspacePicker` 则填充页面局部 Session Intent 主视觉区的 `conversation.hero.workspace` slot；两个界面使用同一套 Workspace 菜单和添加流程。
 
-该浏览器通过全局运行时钩子将 Session 行渲染为分组或扁平形式，并负责 Workspace 添加／重命名／重排序以及 Workspace 内的 Session 重排序。每个 Workspace 会记住自身是关闭还是显示 Session；打开后默认显示五条 Session，其余条目通过临时的**展开其余**控件显示，而关闭并重新打开整个 Workspace 后会恢复为五条。Workspace 列表基线就绪后，浏览器持久化的展开状态与 Session 顺序记录只保留当前 Workspace id 和 Ungrouped。视图选项把分组方式和一份浏览器持久化的 Session 顺序放在一起：进入**最近更新**时执行一次完整的时间排序，后续 user prompt 或 steer 会将对应 Session 置顶一次；进入**手动排序**则保留所有当前位置并停用后续置顶。两种模式下的拖拽都会编辑当前顺序，手动模式下的拖拽还会更新 Host Workspace 记账。无论采用哪种 Session 顺序，Workspace 拖拽顺序都由 Host 持久化。
+该浏览器通过全局运行时钩子将 Session 行渲染为分组或扁平形式，并负责 Workspace 添加／重命名／重排序以及分组内的 Session 重排序。每个 Workspace 会记住自身是关闭还是显示 Session；打开后默认显示五条 Session，其余条目通过临时的**展开其余**控件显示，而关闭并重新打开整个 Workspace 后会恢复为五条。Workspace 列表基线就绪后，浏览器持久化的展开状态与 Session 顺序记录只保留当前 Workspace id 和 Ungrouped。视图选项把分组方式和每个分组各自的一份浏览器持久化 Session 顺序放在一起：真实 Workspace 从 `WorkspaceView.sessionIds` 初始化，Ungrouped 则从最近更新时间顺序初始化。进入**最近更新**时会执行一次完整的时间排序，后续 user prompt 或 steer 会将对应 Session 置顶一次；进入**手动排序**则保留所有当前位置并停用后续置顶。两种模式下的拖拽都会编辑当前顺序；真实 Workspace 在手动模式下的拖拽还会更新 Host Session 记账，而 Ungrouped 因没有 Workspace 持有其中的 Session，其顺序始终只保存在浏览器本地。无论采用哪种 Session 顺序，Workspace 拖拽顺序都由 Host 持久化。
 
 折叠搜索是视图和添加操作旁的一枚区头按钮。激活后，输入框会扩展并占据区头；点击外部只会收起经清除首尾空白后为空的查询，而清除控件总会重置并收起搜索。非空白查询会以单一扁平结果列表替代任一浏览模式：不区分大小写的标题和 Workspace 子串匹配项会立即显示，经 250 ms 防抖的 Host 请求则会加入经过排序的当前对话内容匹配项及其摘要片段。英文搜索输入框及其防御性请求路径会移除 NUL，将查询限制在传输 schema 规定的 500 个 UTF-16 代码单元内且不会拆分代理项对，并保留现有的防抖与取消行为。每次新查询都会中止前一个请求；内容搜索失败时，元数据匹配项仍会显示，同时给出警告。列表最多显示 20 条结果，并会在查询过宽时提示用户缩小范围；打开所选 Session 时既不会清除查询，也不会跳转至特定事件。
 

packages/client/ui-workspace/src/client/WorkspaceBrowser.tsx

@@ -130,7 +130,8 @@ function ViewOptionsMenu({ groupBy, orderBy, onGroupPick, onOrderPick, t }: {
 
 /** In-flight root-row drag: source identity plus the current insert marker. */
 interface DragState {
-  workspaceId: WorkspaceId
+  /** Workspace id, or {@link UNGROUPED_KEY} for the browser-local loose-session account. */
+  workspaceKey: string
   sessionId: SessionNode['id']
   /** Row the marker sits on and which half (insert above/below it). */
   over: { id: SessionNode['id']; half: 'before' | 'after' } | null
@@ -227,13 +228,22 @@ function SessionTree({
     () => Object.entries(workspaceExpansion).filter(([, expanded]) => expanded).map(([key]) => key),
     [workspaceExpansion],
   )
+  const ungroupedSessionIds = useMemo(() => {
+    const accounted = new Set(workspaces.flatMap(workspace => workspace.sessionIds))
+    return list.ids.filter(id => list.byId[id] !== undefined && !accounted.has(id))
+  }, [list, workspaces])
   useEffect(() => {
     if (list.phase !== 'ready') return
     const switchedToUpdated = previousOrderBy.current !== 'updated' && orderBy === 'updated'
     previousOrderBy.current = orderBy
-    for (const workspace of workspaces) {
-      const key = workspace.workspaceId as string
-      const sessionIds = workspace.sessionIds.filter(id => list.byId[id] !== undefined)
+    const accounts = [
+      ...workspaces.map(workspace => ({
+        key: workspace.workspaceId as string,
+        sessionIds: workspace.sessionIds.filter(id => list.byId[id] !== undefined),
+      })),
+      { key: UNGROUPED_KEY, sessionIds: ungroupedSessionIds },
+    ]
+    for (const { key, sessionIds } of accounts) {
       const previousOrder = recentSessionOrder[key]
       const previousUpdatedAt = recentSessionUpdatedAt[key] ?? {}
       let nextOrder = reconciledSessionOrder(sessionIds, previousOrder)
@@ -266,7 +276,7 @@ function SessionTree({
         syncRecentSessions(key, nextOrder.map(id => id as string), nextUpdatedAt)
       }
     }
-  }, [list, orderBy, recentSessionOrder, recentSessionUpdatedAt, syncRecentSessions, workspaces])
+  }, [list, orderBy, recentSessionOrder, recentSessionUpdatedAt, syncRecentSessions, ungroupedSessionIds, workspaces])
   const orderedWorkspaces = useMemo(() => {
     return workspaces.map((workspace) => {
       const stored = recentSessionOrder[workspace.workspaceId as string]
@@ -274,16 +284,25 @@ function SessionTree({
       return { ...workspace, sessionIds }
     })
   }, [recentSessionOrder, workspaces])
+  const orderedUngroupedSessionIds = useMemo(
+    () => reconciledSessionOrder(ungroupedSessionIds, recentSessionOrder[UNGROUPED_KEY]),
+    [recentSessionOrder, ungroupedSessionIds],
+  )
   const groups = useMemo(
-    () => deriveGroups(list, orderedWorkspaces, archivedSessionIds, { expandedProjects }),
-    [list, orderedWorkspaces, archivedSessionIds, expandedProjects],
+    () => deriveGroups(list, orderedWorkspaces, archivedSessionIds, {
+      expandedProjects,
+      ...(recentSessionOrder[UNGROUPED_KEY] === undefined
+        ? {}
+        : { ungroupedOrder: recentSessionOrder[UNGROUPED_KEY] }),
+    }),
+    [list, orderedWorkspaces, archivedSessionIds, expandedProjects, recentSessionOrder],
   )
   const now = Date.now()
   const commitSessionDrag = (activeDrag: DragState, over: NonNullable<DragState['over']>): void => {
     if (sessionDropCommitted.current) return
     sessionDropCommitted.current = true
     setDrag(null)
-    const group = groups.find(candidate => candidate.workspaceId === activeDrag.workspaceId)
+    const group = groups.find(candidate => candidate.key === activeDrag.workspaceKey)
     if (group === undefined) return
     const targetIndex = group.sessions.findIndex(session => session.id === over.id)
     if (targetIndex === -1) return
@@ -294,14 +313,16 @@ function SessionTree({
       ? group.sessions.length
       : group.sessions.findIndex(session => session.id === anchor)
     if (sourceIndex !== -1 && (anchorIndex === sourceIndex || anchorIndex === sourceIndex + 1)) return
-    const account = orderedWorkspaces.find(workspace => workspace.workspaceId === activeDrag.workspaceId)
-    if (account === undefined) return
-    const nextOrder = account.sessionIds.filter(id => id !== activeDrag.sessionId)
+    const accountSessionIds = activeDrag.workspaceKey === UNGROUPED_KEY
+      ? orderedUngroupedSessionIds
+      : orderedWorkspaces.find(workspace => workspace.workspaceId === activeDrag.workspaceKey)?.sessionIds
+    if (accountSessionIds === undefined) return
+    const nextOrder = accountSessionIds.filter(id => id !== activeDrag.sessionId)
     const insertAt = anchor === undefined ? nextOrder.length : nextOrder.indexOf(anchor)
     nextOrder.splice(insertAt === -1 ? nextOrder.length : insertAt, 0, activeDrag.sessionId)
-    setRecentSessionOrder(activeDrag.workspaceId, nextOrder.map(id => id as string))
-    if (orderBy === 'updated') return
-    insertSessionBefore(activeDrag.workspaceId, activeDrag.sessionId, anchor).catch((reason: unknown) => {
+    setRecentSessionOrder(activeDrag.workspaceKey, nextOrder.map(id => id as string))
+    if (orderBy === 'updated' || activeDrag.workspaceKey === UNGROUPED_KEY) return
+    insertSessionBefore(activeDrag.workspaceKey as WorkspaceId, activeDrag.sessionId, anchor).catch((reason: unknown) => {
       console.warn('session reorder rejected:', reason)
     })
   }
@@ -427,15 +448,13 @@ function SessionTree({
                 ? group.sessions
                 : group.sessions.slice(0, COLLAPSED_SESSION_LIMIT)
               ).map((node) => {
-              // Draggable: real-workspace session rows. The drag
-              // never leaves its group — rows of other groups show no markers
-              // and reject drops (visual movement confined to this section).
-                const draggable = group.workspaceId !== undefined
-                const sameGroupDrag = drag !== null && drag.workspaceId === group.workspaceId
-                const dragProps = !draggable || group.workspaceId === undefined ? undefined : {
+              // Session drag never leaves its group. Ungrouped writes only the
+              // browser-local account; real Workspaces may also write Host order.
+                const sameGroupDrag = drag !== null && drag.workspaceKey === group.key
+                const dragProps = {
                   start: () => {
                     sessionDropCommitted.current = false
-                    setDrag({ workspaceId: group.workspaceId as WorkspaceId, sessionId: node.id, over: null })
+                    setDrag({ workspaceKey: group.key, sessionId: node.id, over: null })
                   },
                   active: sameGroupDrag,
                   marker: sameGroupDrag && drag.over?.id === node.id ? drag.over.half : null,

packages/client/ui-workspace/src/client/tree.ts

@@ -78,6 +78,8 @@ export interface SearchResultSet {
 /** Viewing state consumed by the derivation. */
 export interface TreeView {
   expandedProjects: readonly string[]
+  /** Browser-local order for Sessions without a backing Workspace account. */
+  ungroupedOrder?: readonly string[]
 }
 
 interface Group {
@@ -139,21 +141,41 @@ function buildGroup(
   order: 'account' | 'recency',
 ): Group {
   const sessions = [...members]
-  // Workspace order is the caller-selected sessionIds; only Ungrouped lacks
-  // an account order and therefore falls back to recency.
+  // Real Workspace order comes from sessionIds. Ungrouped falls back to
+  // recency until the browser supplies its persisted local order.
   if (order === 'recency') sessions.sort(byRecency)
   return { key, workspaceId, cwd, createdAt, label, sessions }
 }
 
+/** Apply a stored Ungrouped order and append newly loose Sessions by recency. */
+function orderedUngrouped(members: readonly SessionSummary[], stored: readonly string[]): SessionSummary[] {
+  const byId = new Map(members.map(session => [session.id as string, session]))
+  const included = new Set<string>()
+  const ordered: SessionSummary[] = []
+  for (const key of stored) {
+    const session = byId.get(key)
+    if (session === undefined || included.has(key)) continue
+    ordered.push(session)
+    included.add(key)
+  }
+  for (const session of [...members].sort(byRecency)) {
+    if (included.has(session.id)) continue
+    ordered.push(session)
+  }
+  return ordered
+}
+
 /**
  * Group Sessions by Host Workspace: one group per entity in stable Host
  * order, with members resolved from sessionIds in their stored order. Sessions
- * outside every Workspace trail in the recency-ordered Ungrouped bucket.
+ * outside every Workspace trail in the browser-local Ungrouped order, which
+ * falls back to recency before that order is initialized.
  */
 function groupByWorkspace(
   list: SessionListState,
   workspaces: readonly WorkspaceView[],
   archived: ReadonlySet<SessionId>,
+  ungroupedOrder: readonly string[] | undefined,
 ): Group[] {
   const groups: Group[] = []
   const accounted = new Set<SessionId>()
@@ -176,7 +198,15 @@ function groupByWorkspace(
     .filter((s): s is SessionSummary =>
       s !== undefined && !accounted.has(s.id) && sessionVisible(s, list.current, archived))
   if (stray.length > 0) {
-    groups.push(buildGroup(UNGROUPED_KEY, undefined, undefined, undefined, UNGROUPED_LABEL, stray, 'recency'))
+    groups.push(buildGroup(
+      UNGROUPED_KEY,
+      undefined,
+      undefined,
+      undefined,
+      UNGROUPED_LABEL,
+      ungroupedOrder === undefined ? stray : orderedUngrouped(stray, ungroupedOrder),
+      ungroupedOrder === undefined ? 'recency' : 'account',
+    ))
   }
   return groups
 }
@@ -225,7 +255,7 @@ export function deriveGroups(
     : (workspaces.find(w => w.sessionIds.includes(list.current as SessionId))?.workspaceId as string | undefined)
         ?? UNGROUPED_KEY
   const groups: GroupNode[] = []
-  for (const g of groupByWorkspace(list, workspaces, archived)) {
+  for (const g of groupByWorkspace(list, workspaces, archived, view.ungroupedOrder)) {
     const expanded = expandedProjects.has(g.key)
     groups.push({
       key: g.key,

packages/client/ui-workspace/tests/tree.spec.ts

@@ -24,8 +24,9 @@ const workspace = (id: string, sessionIds: string[], title = id): WorkspaceView
   workspaceId: wid(id), path: `/projects/${id}`, title,
   sessionIds: sessionIds.map(sid), createdAt: '2026-01-01T00:00:00.000Z', updatedAt: '2026-01-01T00:00:00.000Z',
 })
-const view = (expandedProjects: readonly string[] = []) => ({
+const view = (expandedProjects: readonly string[] = [], ungroupedOrder?: readonly string[]) => ({
   expandedProjects,
+  ...(ungroupedOrder === undefined ? {} : { ungroupedOrder }),
 })
 const noArchive: readonly SessionId[] = []
 const archived = (...ids: string[]): readonly SessionId[] => ids.map(sid)
@@ -54,6 +55,19 @@ describe('deriveGroups', () => {
     expect(groups[1]!.sessions.map(session => session.id)).toEqual([sid('loose')])
   })
 
+  it('applies stored Ungrouped order and appends new loose Sessions by recency', () => {
+    const sessions = list(summary('one', 3), summary('two', 2), summary('new', 4))
+    const groups = deriveGroups(
+      sessions,
+      [],
+      noArchive,
+      view([UNGROUPED_KEY], ['two', 'stale', 'two']),
+    )
+    expect(groups[0]!.sessions.map(session => session.id)).toEqual([
+      sid('two'), sid('new'), sid('one'),
+    ])
+  })
+
   it('shows only the current blank session in its Workspace count and tree', () => {
     const currentBlank = { ...summary('current-blank', 5), blank: true }
     const staleBlank = { ...summary('stale-blank', 4), blank: true }

packages/client/ui-workspace/tests/workspace-browser.spec.tsx

@@ -9,6 +9,7 @@ import { makeTranslate } from '@deepseek-ai/dsh-client-test-runtime'
 import { zh as commonZh } from '@deepseek-ai/dsh-client-locale/src/locales/zh.ts'
 import type { WorkspaceBrowserProps } from '../src/client/contract/slots.ts'
 import { createWorkspaceViewStore } from '../src/client/stores.ts'
+import { UNGROUPED_KEY } from '../src/client/tree.ts'
 import { WorkspaceBrowser } from '../src/client/WorkspaceBrowser.tsx'
 import { zh } from '../src/client/locales.ts'
 
@@ -111,8 +112,8 @@ describe('WorkspaceBrowser', () => {
     rerender(b, { useWorkspaces: hook(workspaceState([])) })
     await waitFor(() => {
       expect(b.store.getSnapshot().workspaceExpansion).toEqual({})
-      expect(b.store.getSnapshot().recentSessionOrder).toEqual({})
-      expect(b.store.getSnapshot().recentSessionUpdatedAt).toEqual({})
+      expect(b.store.getSnapshot().recentSessionOrder).toEqual({ [UNGROUPED_KEY]: [] })
+      expect(b.store.getSnapshot().recentSessionUpdatedAt).toEqual({ [UNGROUPED_KEY]: {} })
     })
   })
 
@@ -776,6 +777,55 @@ describe('WorkspaceBrowser', () => {
     expect(insertSessionBefore).toHaveBeenCalledTimes(1)
   })
 
+  it('persists Ungrouped drag order in both modes without writing a Host Workspace account', async () => {
+    const insertSessionBefore = vi.fn(async () => {})
+    const sessions = sessionState([summary('one', 3), summary('two', 2), summary('three', 1)])
+    const b = mount({
+      useSessions: hook(sessions),
+      useWorkspaces: hook(workspaceState([])),
+      insertSessionBefore,
+    })
+    fireEvent.click(screen.getByText('未分组'))
+
+    const dragAfter = (sourceTitle: string, targetTitle: string): void => {
+      const source = screen.getByText(sourceTitle).closest('[role="treeitem"]') as HTMLElement
+      const target = screen.getByText(targetTitle).closest('[role="treeitem"]') as HTMLElement
+      target.getBoundingClientRect = () => ({
+        top: 150, bottom: 184, left: 0, right: 200, width: 200, height: 34, x: 0, y: 150, toJSON: () => ({}),
+      })
+      fireEvent.dragStart(source, { dataTransfer: dragData() })
+      fireDrag(target, 'drop', 180)
+    }
+
+    dragAfter('one', 'three')
+    expect(b.store.getSnapshot().recentSessionOrder[UNGROUPED_KEY]).toEqual(['two', 'three', 'one'])
+    dragAfter('two', 'one')
+    expect(b.store.getSnapshot().recentSessionOrder[UNGROUPED_KEY]).toEqual(['three', 'one', 'two'])
+    expect(insertSessionBefore).not.toHaveBeenCalled()
+
+    fireEvent.click(screen.getByRole('button', { name: '视图选项' }))
+    fireEvent.click(screen.getByRole('menuitem', { name: '最近更新' }))
+    await waitFor(() => {
+      expect(b.store.getSnapshot().recentSessionOrder[UNGROUPED_KEY]).toEqual(['one', 'two', 'three'])
+    })
+    dragAfter('one', 'three')
+    expect(b.store.getSnapshot().recentSessionOrder[UNGROUPED_KEY]).toEqual(['two', 'three', 'one'])
+    expect(insertSessionBefore).not.toHaveBeenCalled()
+
+    b.view.unmount()
+    const restored = mount({
+      useSessions: hook(sessions),
+      useWorkspaces: hook(workspaceState([])),
+      insertSessionBefore,
+    })
+    expect(restored.store.getSnapshot().recentSessionOrder[UNGROUPED_KEY]).toEqual(['two', 'three', 'one'])
+    expect(screen.getAllByRole('treeitem').slice(1).map(row => row.textContent)).toEqual([
+      expect.stringContaining('two'),
+      expect.stringContaining('three'),
+      expect.stringContaining('one'),
+    ])
+  })
+
   it('still sends the reorder when the dragged row left the group mid-drag', () => {
     const insertSessionBefore = vi.fn(async () => {})
     const sessions = sessionState([summary('one', 2), summary('two', 1)])