feat: Extend Swagger Coverage for controller UploadController

[matiasperrone-exo]

Task;

Ref: https://app.clickup.com/t/86b6wkgqj

[caseylocker]

1. Resolve merge conflicts - PR is currently CONFLICTING
2. Fix path - Change /api/v1/files/upload → /api/public/v1/files/upload
3. Fix security scheme - Replace [['bearer' => []]] with a defined OAuth2 scheme (e.g., summit_oauth2) or define a new security scheme
4. Fix tag casing - Change files → Files

Should this be moved from UploadController::upload() to OAuth2ChunkedFilesApiController::uploadFile() since that's what the route uses in public_api.php?
Route::post('upload', 'OAuth2ChunkedFilesApiController@uploadFile');