Banner image upload fails with "The banner image field contains a file path that is not permitted"

Start in src/Filament/Pages/Settings/ManageTheme.php and inspect the app_banner FileUpload definition, especially preventFilePathTampering(), alongside the current Filament and Livewire versions. Reproduce the dashboard upload, compare behavior with that option removed, and confirm that a valid supported banner image is accepted and saved without the file-path validation error.

When attempting to upload a new banner image from the Cachet 3 dashboard, the upload fails with:

The banner image field contains a file path that is not permitted

The image is a valid supported image type and the upload reaches the Livewire temporary upload stage successfully, but the Cachet settings form subsequently rejects the file.

Environment
Cachet: cachethq/core dev-main
Commit: 5ee03e64e7ecc7eae085b05cce4740477da91954

Filament Forms: v5.7.6
Livewire: v4.4.2

Steps to reproduce

Log into the Cachet 3 administration dashboard.
Navigate to the theme/settings page.
Select a new banner image.
Save the settings.
The form returns:
The banner image field contains a file path that is not permitted

Cause
The app_banner field in:
src/Filament/Pages/Settings/ManageTheme.php

currently uses:
FileUpload::make('app_banner')
   ->acceptedFileTypes((array) config('cachet.uploads.image_mime_types'))
   ->maxSize((int) config('cachet.uploads.max_size'))
   ->preventFilePathTampering()

The issue appears to be related to preventFilePathTampering().

Filament's validation checks submitted string file paths against the original path associated with the record. With a newly uploaded banner, the resulting path does not match the existing/original app_banner value, resulting in the upload being rejected as an unauthorised file path.

Workaround
Removing:
->preventFilePathTampering()

from the app_banner FileUpload definition allows the banner to upload successfully.

The resulting configuration is:
FileUpload::make('app_banner')
   ->acceptedFileTypes((array) config('cachet.uploads.image_mime_types'))
   ->maxSize((int) config('cachet.uploads.max_size'))
   ->imageEditor()
   ->label(('cachet::settings.manage_theme.app_banner_label'))
   ->hiddenLabel()
   ->helperText(('cachet::settings.manage_theme.app_banner_helper'))
   ->disk((string) config('cachet.uploads.disk'))
   ->columnSpanFull()

Expected behaviour
A valid supported image should be accepted as the new banner image and saved successfully.
Actual behaviour
The upload fails validation with:
The banner image field contains a file path that is not permitted

Suggested investigation
Please investigate the use of:
->preventFilePathTampering()

on the app_banner field and its interaction with the current Filament/Livewire versions.
Removing this option resolves the issue, suggesting that the banner upload is being incorrectly treated as an unauthorised existing file path rather than a legitimate newly uploaded file.
This may be a Cachet/Filament/Livewire compatibility issue rather than an issue with the uploaded image itself.