Upload dialog: fix allowed characters for filename

[distantnative]

This PR …

Consistent with change filename dialog:

kirby/config/areas/files/dialogs.php

Line 29 in c1e6ff7

'allow' => 'a-z0-9@._-',

Fixes

• Upload dialog: allows @, . and _ in filenames to be consistent with other filename rules
  Filename sanitization rules are inconsistent #6461
• $file->changeName() now sanitizes new filenames with. included correctly

For review team

• Add changes & docs to release notes draft in Notion

[afbora]

@distantnative I found something . Could you check whether it's bug or not? I think there is an inconsistency about @ char.

1. Select a file from files section
2. Set filename as file.a@b_c-d in dialog before upload and upload it
3. file.a@b_c-d.jpg files will be uploaded successfully and you'll see in section
4. Try to rename the file with file.a@b_c-de (append just e)
5. You will see that @ is gone as file.a-b-c-de.jpg

[distantnative]

@afbora Good catch. This was actually its own bug where $file->changeName() would apply F::safeName() even though passing the name string without extension. So when that name contained a ., F::safeName() would consider that the separator between base name and extension. Now using F::safeBasename().