ComfyUI exposes commands and menuCommands for the menu bar, but the
workflow tab context menu is built inside WorkflowTab.vue and has no
extension hook. Reuse the registered create/update actions and inject
the entries into the reka-ui portal, the same fallback the Graph menu
already uses.
The entries sit above the tab-close group. Clicking one activates the
right-clicked tab through app.extensionManager.workflow.openWorkflow
(the switch the native Save/Export entries use), so the action targets
that tab's graph instead of whichever tab was active. Update is enabled
from that tab's own lm_source marker and link-status check, and a menu
instance is only enhanced once.