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

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; the existing-folder and create-new actions first create a real Workspace through the object layer, then select it. Create-new 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.

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 Workspace rename/delete controls — the picker supports selection and creation only.
Existing-folder entry is manual path input only — Host creation failures are shown in the modal.