fix(client): prune removed workspace view state

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

@@ -625,6 +625,7 @@ export function WorkspaceBrowser({
   t,
 }: WorkspaceBrowserProps) {
   const workspaces = useWorkspaces(state => state.items)
+  const workspacePhase = useWorkspaces(state => state.phase)
   const archivedSessionIds = useWorkspaces(state => state.archivedSessionIds)
   // Live occupancy of this surface's directory-flow hole (the same source the
   // flow reads): a composition without a picking affordance can add nothing.
@@ -637,6 +638,13 @@ export function WorkspaceBrowser({
   const workspaceExpansion = useStore(s => s.workspaceExpansion)
   const recentSessionOrder = useStore(s => s.recentSessionOrder)
   const recentSessionUpdatedAt = useStore(s => s.recentSessionUpdatedAt)
+  useEffect(() => {
+    if (workspacePhase !== 'ready') return
+    actions.retainWorkspaceKeys([
+      UNGROUPED_KEY,
+      ...workspaces.map(workspace => workspace.workspaceId as string),
+    ])
+  }, [actions.retainWorkspaceKeys, workspacePhase, workspaces])
   // The query outlives the tree and the input (both wide-only) so collapsing
   // does not silently drop an in-progress filter.
   const [query, setQuery] = useState('')

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

@@ -32,6 +32,7 @@ type WorkspaceViewActions = {
   setGroupBy: (draft: WorkspaceViewState, mode: WorkspaceGroupBy) => void
   setOrderBy: (draft: WorkspaceViewState, mode: WorkspaceOrderBy) => void
   setWorkspaceExpanded: (draft: WorkspaceViewState, key: string, expanded: boolean) => void
+  retainWorkspaceKeys: (draft: WorkspaceViewState, workspaceKeys: readonly string[]) => void
   syncRecentSessions: (
     draft: WorkspaceViewState,
     workspaceKey: string,
@@ -59,6 +60,18 @@ export function createWorkspaceViewStore(): EngineStoreHandle<WorkspaceViewState
       setGroupBy: (d, mode: WorkspaceGroupBy) => { d.groupBy = mode },
       setOrderBy: (d, mode: WorkspaceOrderBy) => { d.orderBy = mode },
       setWorkspaceExpanded: (d, key: string, expanded: boolean) => { d.workspaceExpansion[key] = expanded },
+      retainWorkspaceKeys: (d, workspaceKeys: readonly string[]) => {
+        const retained = new Set(workspaceKeys)
+        d.workspaceExpansion = Object.fromEntries(
+          Object.entries(d.workspaceExpansion).filter(([key]) => retained.has(key)),
+        )
+        d.recentSessionOrder = Object.fromEntries(
+          Object.entries(d.recentSessionOrder).filter(([key]) => retained.has(key)),
+        )
+        d.recentSessionUpdatedAt = Object.fromEntries(
+          Object.entries(d.recentSessionUpdatedAt).filter(([key]) => retained.has(key)),
+        )
+      },
       syncRecentSessions: (d, workspaceKey: string, order: string[], updatedAt: Record<string, number>) => {
         d.recentSessionOrder[workspaceKey] = order
         d.recentSessionUpdatedAt[workspaceKey] = updatedAt