API - can_be_stitched on video resources

API v2 now exposes the can_be_stitched boolean on video resources so developers can read and update whether a public video may be used as a source for content stitching.

• Request can_be_stitched through ?fields=can_be_stitched on GET /videos/{id} or GET /videos
• Provide value when creating a video with POST /videos or updating one with PATCH /videos/{id}.

The field is non-nullable, defaults to false, and is not included in default responses, so existing integrations are unchanged.

Content stitching requires a public video. On private or password-protected videos, setting can_be_stitched to true may read back as false. Changing a video to private disables stitching. Listing filters are unchanged.