docs(web): record workspace sidebar behavior

packages/client/ui-workspace/README.md

@@ -4,7 +4,9 @@ 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 the Workspace add/rename and in-Workspace reorder flows. 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.
+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. View options combine grouping with Session order: **Manual** follows the Host Workspace account, while **Last updated** keeps a browser-local editable order and moves a Session to the front whenever a newer `updatedAt` arrives. 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 an empty query, 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.
 
 The picker lists real Host Workspace entities through the global `useWorkspaces` hook. Selecting a Workspace invokes the slot owner's `onPick` callback to retarget the frontend Session object. Distinct canonical paths remain separate id-keyed Workspaces when their basenames and display titles match; the sidebar hover detail exposes the full path. Each registration declares a **directory-flow child hole** (`single` kind: `conversation.hero.workspace.directoryFlow` / `sidebar.workspaces.directoryFlow`) that the composed picker package's client half fills with its picking interaction — the [`-native`](../../host/directory-picker-native/README.md) backend's renderless OS-chooser driver today, an in-app browsing dialog under a `-browse` composition. The flat **Add workspace...** action renders only while the surface's hole is occupied (occupancy read per menu render; an empty hole means the composition has no picking affordance — the seam's documented no-flow default, under which the sidebar header drops its add button rather than offering a dead one). This package owns the trigger and the adoption: the occupant reports one picked path per open through the hole's owner conversation (`open`/`busy`/`onPicked`/`onCancel`/`onError`), and the owner adopts it through the object layer, selecting the committed Workspace only after its list projection has refreshed; cancellation is silent, and errors land in the retryable folder dialog whose **Choose again** reopens the flow. Adding has exactly one route: the occupant's own create-folder affordance already covers a brand-new directory, so no separate create-by-name dialog exists. A menu only appears where there is something to choose between — with no Workspace listed, the anchor gesture raises the flow directly instead of a one-row popover, and it waits for the list baseline before treating an empty list as final. The runtime Session and Workspace services own materialization. The Workspace row's Delete action opens a confirmation that states the retention boundary, blocks duplicate submission, and keeps failures open; success removes the group while its Sessions remain under Ungrouped. The Session row's Rename action opens the same browser-owned dialog pattern prefilled with the row's display title: no client-side conflict rule exists (the host normalizes and may reject with `title-invalid`, rendered in the dialog alert), and confirming an unchanged title is deliberately allowed — it pins the current automatic title against regeneration. The Session row's Archive action commits without a confirmation dialog (non-destructive: the log and the workspace accounting slot remain) through `ctx.workspaces.archiveSession`; the row disappears from every grouping surface — workspace groups, Ungrouped, content search, and the flat list — when the archive-set echo lands, and failures are console diagnostics that leave the tree unchanged. A blank New Session row is a pure placeholder: it renders no row menu and no time label (nothing has happened in it yet), so rename, fork, and archive first apply once the first prompt lands.