N8N examples

POST /api/v1/projects
  → { project: { id } }

POST /api/v1/projects/:id/messages
  → { fragmentId, status: "generating" }

loop: GET /api/v1/fragments/:fragmentId
  until animationUrl !== null

GET /api/v1/fragments/:fragmentId/signed-video
  → { signedUrl }

... (same generation flow above)

loop: GET /api/v1/fragments/:fragmentId/evals
  until evalPipelineRun.status === "COMPLETED"

→ write rubric score, per-kind status to a sheet

→ optionally: GET /api/v1/evals/pipeline-runs/:pipelineRunId/issues
    → write individual issues to a separate sheet tab

POST /api/v1/fragments/:fragmentId/music
  { "random": true }
  → { ok: true, trackSlug, track }

loop: GET /api/v1/fragments/:fragmentId/music
  until status === "completed" or "failed"

GET /api/v1/fragments/:fragmentId/signed-video
  → refreshed URL with audio