Files: drag tabs to reorder, and a right-click menu in the tree
Open tabs in Files now reorder by dragging, or with ⌥⇧← and ⌥⇧→ on a focused tab, and keep their order through a reload. Right-clicking a file or folder in the tree opens a menu: New file and New folder inside a folder, Rename in place, Duplicate, Copy path, Collapse and Delete.
A rename moves a folder's files in one change, and open tabs and unsaved edits follow it. A name that's taken is refused in the row with the reason. The app's top folders, api/models and a model's folder keep their names. F2 renames the focused row, ⌘⌫ deletes it and ⌥⌘C copies its path.