Attachments.txt

To upload an attachment, use a POST with file as the contents to:
/api/sandbox/testcase/2/attachment

This works:
curl --location "dokimion4.psonet/api/sandbox/testcase/18/attachment" -H "Whoru-Api-Token: abc" -F "file=@ParaNextDocumentLinks.txt" -F "fileId=ParaNextDocumentLinks.txt" -F "initialPreview=[]" -F "initialPreviewConfig=[]" -F "initialPreviewThumbTags=[]"

To see attachment in test case do a GET to the testcase:
/api/sandbox/testcase/2
The response is:
{
	"attachments": [
		{
			"id": "33a43c7f-9211-4498-af03-3b069ef6db66",
			"title": "Wycliffe-The-Finish-Line-2024-April.pdf",
			"createdBy": "admin",
			"createdTime": 1713206615735,
			"dataSize": -1
		}
	],
	"automated": false,
	"locked": false,
	"broken": false,
	"launchBroken": false,
	"id": "2",
	"deleted": false,
	"createdTime": 0,
	"lastModifiedTime": 1713206615745,
	"lastModifiedBy": "admin",
	"attributes": {},
	"metaData": {}
}

To remove attachment, do a DELETE with no parameters to:
/api/sandbox/testcase/2/attachment/33a43c7f-9211-4498-af03-3b069ef6db66
Response is the current value of the test case.

To download attachment, do a GET using the attachment's ID:
api/sandbox/testcase/18/attachment/d7a0286f-bede-4609-a301-3caa7eba128e


Thoughts:
On downloading a test case, download the attachments, which will overwrite existing ones, which is OK if they are the same.  We want to see newer ones.

On uploading, look at the ID's in the test case on disk.  
If the attachment for the ID exists on the server, download it and compare to what is on disk. 
  If different, upload attachment.
If we can't download that ID, upload the file.  
Redownload the test case after all attachments are handled if we uploaded any to get the new IDs for the newly uploaded attachments.