fix #6475: ui: upload: only show the file name of the selected file

For privacy reasons, browsers do not expose the real path of a selected
file and prefix its name with 'C:\fakepath\' instead, on every
platform. The file field of the upload window shows this value as is,
which confuses users on Linux or macOS clients.

Show the name of the selected file object instead. Only the displayed
value changes, the upload itself uses the file object and is not
affected.

Signed-off-by: Michal Fox <me@dualfroz.com>
Reviewed-by: Max R. Carrara <m.carrara@proxmox.com>
Tested-by: Max R. Carrara <m.carrara@proxmox.com>
Link: https://lore.proxmox.com/20260926084935.7-1-me@dualfroz.com

www/manager6/window/UploadToStorage.js

@@ -167,6 +167,8 @@ Ext.define('PVE.window.UploadToStorage', {
                 (fileInput.files[0] && Proxmox.Utils.format_size(fileInput.files[0].size)) || '-',
             );
             vm.set('mimetype', (fileInput.files[0] && fileInput.files[0].type) || '-');
+            // browsers hide the real path behind 'C:\fakepath\', so only show the file name
+            input.setRawValue(fileInput.files[0]?.name ?? '');
         },
 
         hashChange: function (field, value) {