[Feature Request] Using custom fields in workflow title templates

Description Description of the problem Currently, it is not possible in Paperless-ngx to access custom fields within workflows (e.g., when automatically generating document titles). While Jinja2 templates were introduced for workflows to enable dynamic titles, paths, or file names, custom fields are apparently not available there. The documentation ([Advanced Usage → Additional Variables]( shows how custom fields can be used in templates in general. However, this logic does not work in the area of workflow title generation. This means that custom fields cannot currently be used in the title templates of a workflow. Why this is important Custom fields are often key metadata that are crucial for meaningful and consistent title assignment, such as invoice numbers, project names, customer codes, or contract IDs. Without access to these fields, you have to make do with less meaningful or redundant titles, which reduces the degree of automation and clarity. Expected …