Follow-up to #74088. With the row-card primitives renamed (`WorkPackageCardComponent` / `WorkPackageCardBoxComponent`) and the polymorphic container adapter (sibling WP) extracted, the deferred row-menu components are the last asymmetric pair in this rename family.

## Naming inconsistency

After the #74088 rename pass, the deferred menus still read as legacy:

Begin of the insertion* End of the insertion Begin of the deletion -End of the deletion `Backlogs::InboxMenuComponent` (`inbox_menu_component.{rb,html.erb}`) Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion `Backlogs::StoryMenuListComponent` (`story_menu_list_component.{rb,html.erb}`) Begin of the insertion


End of the insertion Begin of the deletion

End of the deletion Issues:

Begin of the insertion* "Story"End of the insertion Begin of the deletion - "Story"End of the deletion terminology survives only here; the rest of the page now talks about work packages and cards. Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion One is `*MenuComponent`, the other is `*MenuListComponent` Begin of the insertion—End of the insertion Begin of the deletion —End of the deletion different suffixes for the same thing (a `Primer::Alpha::ActionMenu::List` for a single row). Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion Neither name reflects that these belong to a row card. Begin of the insertion


End of the insertion Begin of the deletion

End of the deletion ## Duplication

The two classes are 95% the same:

Begin of the insertion* End of the insertion Begin of the deletion -End of the deletion Identical predicates: `show_move_submenu?`, `show_move_items?`, `show_move_to_sprint?`, `allowed_to_manage_sprint_items?`, `first_item?`, `last_item?`. Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion Identical `build_move_menu` / `build_move_item` shape; only the route helper differs (`reorder_project_backlogs_inbox_path` vs `reorder_project_backlogs_work_package_path`). Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion Templates are near-clones Begin of the insertion—End of the insertion Begin of the deletion —End of the deletion same item ids, same icons, same submenu structure; only the move and move-to-sprint-dialog hrefs differ. Begin of the insertion


End of the insertion Begin of the deletion

End of the deletion ## Proposed direction

Consolidate into a single `Backlogs::WorkPackageCardMenuComponent` (working name) that takes `work_package`, the polymorphic `container_adapter`, `max_position`, `open_sprints_exist`, and `current_user`. The route helpers become `container_adapter.reorder_path(...)` and `container_adapter.move_to_sprint_dialog_path(...)`.

Rendering controllers (`Backlogs::InboxController#menu` and `Backlogs::WorkPackagesController#menu`) keep their distinct turbo-frame endpoints but render the same component with their own adapter instance.

Translation keys live under one shared namespace; current keys differ only cosmetically.

## Out of scope

Begin of the insertion* End of the insertion Begin of the deletion -End of the deletion Any change to the row-card menu **trigger** (`work_package_card_component/menu.rb`) Begin of the insertion— that'sEnd of the insertion Begin of the deletion — that'sEnd of the deletion the in-card icon button, not the deferred list, and is already shared. Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion DnD reorder semantics; this WP only renames and de-duplicates the menu list. Begin of the insertion


End of the insertion Begin of the deletion

End of the deletion ## Acceptance

Begin of the insertion* End of the insertion Begin of the deletion -End of the deletion Single component class drives both the inbox-context and sprint-context deferred menus. Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion Old class names deleted (no compatibility aliases). Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion Existing component specs converge into one suite, parameterised over container kind. Begin of the insertion

* End of the insertion Begin of the deletion
-End of the deletion Visual diff against Lookbook previews shows no change. Begin of the insertion


<br>End of the insertion Begin of the deletion

Depends on: #74554 (sibling WP "Extract a polymorphic container adapter for shared card primitives").
Parent: #74088End of the deletion