OpenAPI definition issues

issues i encountered in the current version of https://sshoc-marketplace-api.acdh-dev.oeaw.ac.at/v3/api-docs

• getInformationContributors don't have unique operation ids, i.e. it's named the same for every category, so we end up with getInformationContributors_1, getInformationContributors_2 etc. Same for the getInformationContributorsForVersion and the merge endpoints
• RelatedItemDto can be a RelatedStepDto (i.e. include workflowId)
• is it possible to create actual query param definitions for facets? the openapi doc currently does not reflect the required params shape, see here
• wrong operationIds:
  • /api/sources/{id}#delete should be "deleteSource" not "deleteTool"
  • /api/concept-search#get should be "searchConcepts" not "searchItems"
• content type "*/*" should be "application/json" for
  • /api/item-search
  • /api/concept-search
  • /api/item-search/autocomplete
  • /api/vocabularies
  • /api/vocabularies/{code}
• /api/workflows/{workflowId}/steps/{stepId}/steps: can this get an operationId less similar to /api/workflows/{workflowId}/steps (both have "createStep")
• can we extract the sort order enum (instead of inlining?)
• in item search, can we give categories a more specific type than Record<string, string>, i.e. use properties instead of additionalProperties in openapi doc?
• similarly, can we give the items-categories response a more specific type (currently also Record<string, string>)
• can we narrow the category property for specific entities? e.g. DatasetDto currently lists the full category enum as allowed values for DatasetDto.category, when it should be narrowed to dataset.
• /api/auth/sign-in endpoint missing
• - document required fields in POST request body / GET response payload. currently all fields are optional (openapi spec default), which does not conform to actual api behavior
• mark fields as nullable when they allow null (e.g. entity.source)
• step.relatedItems defaults to null instead of an empty array (as it does for other entity types)
• the requestbody schema for properties on e.g. POST /api/datasets says that it takes a DatasetCore and therefore concept is a ConceptId, i.e. requires code, vocabulary, and uri. uri does not seem to actually be required.
• Resource.inputStream is an object type without properties

thanks

edit: (2) and (4) fixed by !20 (merged)