Every file has a ⋯ menu: on its card, on its row in the list, and in the window when the file is open.
The file menu with Rename, Send to Agent, Add to project, Unstar, Download and Delete, light themeThe file menu with Rename, Send to Agent, Add to project, Unstar, Download and Delete, dark theme
ActionWhat it does
RenameGives the file a new name
Send to AgentStarts a new chat with the file in it
Add to projectPuts a presentation, design or motion video in a project. Only these have it
Star / UnstarMarks the file as a favourite, or takes the mark off
DownloadSaves the file to your device
DeleteDeletes the file for good

Rename

Type the new name and choose Rename, or press Enter. The extension stays as it is: the dialog says which one it keeps, so .png stays .png.
The Rename file dialog, light themeThe Rename file dialog, dark theme

Send to Agent

Send to Agent opens a new chat with the file already in the message, so you can ask about it or ask for something made from it. A presentation, design or motion video goes in as a mention, such as @NovaCard seed deck: the agent opens the document itself and can change it.

Star

Starred files show Unstar in their menu, with a yellow star. To see only them, choose Favourites only in the filter. See Filter and sort.

Add to project

Presentations, designs and motion videos can sit in one project at a time. Everyone in the project can open the document, and the project’s editors can change it. The list shows the projects where you can edit, with a tick next to the one the document is in now. Pick another project to move it there, or Take out of the project to keep it only in your Library.
The Add to project dialog with four projects and NovaCard ticked, light themeThe Add to project dialog with four projects and NovaCard ticked, dark theme
What a project does with its documents is on Artifacts of a project.

Delete

Delete asks first, then deletes the file for good. A file with earlier versions is deleted with all of them, and the dialog says how many.
The Delete file dialog, light themeThe Delete file dialog, dark theme

Several files at once

In the list view, tick the files you want. The tick in a day’s header picks the whole day. A bar at the bottom counts what you picked: Delete deletes them all after you confirm, and × clears the choice.
The list view with three files ticked and the bar 3 selected, Delete, light themeThe list view with three files ticked and the bar 3 selected, Delete, dark theme