List results and artifacts

GET /api/v1.0/validate/runs?project_id=&repo=     # decision records, newest first, each with the spec_hash it ran against
GET /api/v1.0/validate/runs/<run_id>              # one run's state and artifacts, with download URLs minted per request
GET /api/v1.0/validate/proposals/<proposal_id>    # a proposal as structured fields plus a tldr