Assessment Configuration: Attach rubric documents

[kartpop]

Is your feature request related to a problem?
Currently, rubric and knowledge documents can only be included inline in the prompt. This limitation impacts the flexibility and usability of the assessor configuration.

Describe the solution you'd like

• Enable the assessor config to attach rubric and knowledge documents, rather than just inline text.
• Ensure attached documents are provided to the LLM as attachments during the assessment process.

Original issue

Context

Currently model answer sheets and knowledge/rubric documents can only be placed inline in the prompt. Ability to attach rubric/knowledge docs in the assessor config is missing.

Acceptance criteria

• Assessor config supports attaching rubric/knowledge documents (not just inline prompt text).
• Attached docs are provided to the LLM as attachments in the assessment path.