[Bug/Improvement]: Consolidate bulk file operation notifications into single progress indicator

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

When performing bulk file operations through the web interface, e.g. moving multiple files into a folder using drag and drop, Nextcloud currently creates individual notifications for each file. This results in notification spam and poor user experience, especially with large numbers of files.

Current behavior:

• Each file operation generates its own toast notification
• Multiple notifications stack up and clutter the interface
• Operations appear slower due to notification overhead
• No clear indication of overall progress

Proposed behavior:

• Single consolidated notification for bulk operations like when Uploading multiple files
• Progress bar showing completion percentage
• Counter displaying "X of Y files processed"
• Clear indication when operation completes
• Reduced visual clutter

Environment:
Nextcloud version: 31.0.7.1
Browser: Firefox 142.0.1

Steps to reproduce

1. Create a folder and multiple files (e.g. 100) in one location in the Files app.
2. Mark all files and drag & drop them into the folder.

Expected behavior

Single consolidated notification for bulk operations with progress bar.

Nextcloud Server version

31

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

MySQL

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

No response

Start with the Files app's bulk drag-and-drop flow and notification handling described in the issue. No files, tests, or entry points are named, so trace how multiple operations create toasts and identify the existing progress behavior for uploads. Done means one consolidated notification shows progress and completion for a bulk operation without notification spam.