Feature: #107697 - Unified file creation in Element Browser 

See forge#107697

Description 

The file creation functionality in the TYPO3 backend has been significantly improved and unified to provide a consistent user experience. Previously, creating new files required navigating to a separate page, which resulted in context loss and an inconsistent interface compared to folder creation.

File creation is now fully integrated into the Element Browser pattern, similar to how folder creation works. This change brings a consistent, modern, and more intuitive workflow to file management.

Key improvements 

Unified interface
File creation now uses the same modal-based Element Browser interface as folder creation, providing a consistent look and feel across all file operations.
Single entry point
The new New File button provides access to all file creation methods: file upload with drag-and-drop, online media (YouTube, Vimeo), and text file creation — all in one unified interface.
Context preservation
The modal interface keeps users in context with the file storage tree visible, eliminating the need to navigate away from the current view.
Advanced upload handling
The new implementation uses the drag-uploader component, which provides sophisticated duplication handling (replace, rename, skip, or use existing), replacing the previous simple "override existing" checkbox.
File extension filtering
File creation forms are automatically filtered based on allowed file types and hidden when no valid file extensions are available for the current context.
Updated button labels
For consistency and clarity, button labels have been updated from Create Folder / Create File to New Folder / New File, better reflecting the nature of the actions.

How to use 

In the File List module, click the New File button in the document header toolbar to open a modal dialog. This modal provides three ways to add files:

  1. Upload files - Click Select & upload files to choose files. The drag-and-drop uploader supports advanced duplication handling, allowing you to choose whether to replace, rename, skip, or use existing files when conflicts occur.
  2. Add online media - Enter a URL from supported online media platforms (YouTube, Vimeo) to add media files directly from the web.
  3. Create text file - Create a new empty text file with supported extensions (based on system configuration).

The modal keeps the file storage tree visible, allowing users to navigate between folders without losing context. All three options are available in a single, unified interface, streamlining the file creation workflow.

The previous Upload file button has been removed.

Impact 

The unified file creation interface provides a significantly improved user experience through better context preservation, advanced duplication handling, and a consistent modal-based workflow.

Editors benefit from having all file creation options in one place, eliminating the need to navigate between different pages for different file operations. The modal-based approach keeps the file storage tree visible, making it easier to work with files across multiple folders within a single, continuous workflow.