CycleArtifactSummary

One artifact produced by a cycle, with a ready-to-use download URL. WS run-detail parity (BE): the cycle-detail response carried a count badge ("1 artifact") but no download path, so the FE could not link to the produced file even though a download endpoint already exists. This summary closes that gap. Read from workstreams.cycle_artifact.

Field	Type	Description
`id`required	`string (uuid)`	Artifact UUID
`name`	`string \| null`	Human display name of the artifact
`file_name`	`string \| null`	Original file name, if any
`artifact_type`required	`string`	Artifact type (e.g. generated_doc)
`size_bytes`	`integer \| null`	Size in bytes, if known
`created_at`required	`string (date-time)`	When the artifact was produced
`download_url`	`string \| null`	Relative path to stream the artifact content: /api/v1/workstreams/cycles/{cycle}/artifacts/{artifact}/download