Start (or restart) a video upload for this link's video consent (Authorization: Bearer <link code>). Returns a 2-hour signed resumable-upload token for a new, never-reused path.
Body: { size, type (video/quicktime | video/mp4), duration_seconds }. 400 too long / too large / wrong type; 409 no video consent yet; 410 expired; 429 too many attempts.
POST
https://api.channelautomation.com/api/field-sales/public/testimonial-links/video-upload