Shared Workspace picker plugin. WorkspaceBrowser is registered into the sidebar's sidebar.workspaces slot and WorkspacePicker into the page-local Session Intent hero's conversation.hero.workspace slot, so both surfaces use the same menu and creation flow.

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. 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 backend's renderless OS-chooser driver today, an in-app browsing dialog under a -browse composition. The flat Open local folder... 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). 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. Create a new workspace retains the name dialog and disables names already present in that list, while the Host remains authoritative for concurrent or non-UI callers. 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.

Both target slots are declared by other plugins, so apply registers through declaration-aware deferral and re-registers after a declaring slot is restored.

Model Experience

None, as the picker is browser chrome; nothing here reaches a model request.

KV Cache effect

None; this package neither assembles nor sends a provider request.

Known Limitations and Deferred Work

No Session deletion or fork control — the Session menu's Fork and Delete rows remain visual-only (Rename is wired); Workspace registration deletion does not delete Sessions.
Native folder selection depends on the local Host carrier — under the -native composition, fixture-only or remote browser deployments cannot open a local operating-system dialog; platform failures are shown in a retryable modal. Remote-capable picking is the -browse composition's in-app flow.