File Upload Support in REST API

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Clear and concise description of the problem

I'm working on an integration for transferring handwritten notes into Anytype. The idea is to convert these notes to searchable PDFs/text and sync them to Anytype. This works well for text content using the current REST API.
However, file uploads don't appear to be supported. I cannot find an endpoint to upload images or PDFs and attach them to objects.

Suggested solution

Add file upload support to the REST API (e.g., POST /v1/spaces/{space_id}/files or multipart upload on object creation).

Alternatively, if there are architectural reasons this isn't feasible for the REST API, guidance on whether the internal gRPC APIwould be a viable approach for self-hosted instances would be helpful.

Alternative

No response

Additional context

No response

Start by reviewing the existing REST API endpoints and the project's OpenAPI materials to understand how objects and attachments are currently represented. Done means defining and implementing a supported upload path for images or PDFs, or documenting whether the internal gRPC API is viable for self-hosted instances.