Overwrite the current draft ontology with a user-edited one

Replace the current draft with a user-edited ontology, staying in (or returning to) DRAFT.

Immediately overrides the ontology GraphService uses for this project (approved_ontology is set alongside ontology), so it goes through the same FalkorDB compatibility check as approve: a retyped already-registered property fails with a 409 and nothing is persisted; additive changes are force-applied into FalkorDB first. Without that, every later graph session's OntologyStore.register() would reject the new approved_ontology and break ingestion/search for the whole project.

Sanitized via sanitize_ontology before either field is written, same as a fresh discovery draft — an instance-value-shaped attribute name (e.g. carried over from a pre-fix draft, or pasted in by hand) never gets persisted, let alone made live.

Allowed only from DRAFT/FAILED — DISCOVERING would race a background discovery task, and APPROVED must go through a fresh propose first (edits after approval reuse the same compatibility check approve runs, not this endpoint).

curl -X PUT "https://deepfellow-server-host/v1/graph/ontology/draft" \  -H "OpenAI-Organization: string" \  -H "OpenAI-Project: string" \  -H "Content-Type: application/json" \  -d '{    "ontology": {}  }'

{
  "id": "string",
  "project_id": "string",
  "state": "discovering",
  "ontology": {},
  "approved_ontology": {},
  "source_file_ids": [
    "string"
  ],
  "boundaries": "string",
  "last_error": "string",
  "warnings": [
    "string"
  ],
  "created_at": "2019-08-24T14:15:22Z",
  "updated_at": "2019-08-24T14:15:22Z"
}

{
  "detail": [
    {
      "loc": [
        "string"
      ],
      "msg": "string",
      "type": "string",
      "input": null,
      "ctx": {}
    }
  ]
}