[Docs] Illustrate Kanvas Designer docs with api-platform-aws design walkthrough

[leecalcote]

Overview

Update Kanvas Designer documentation to use Jordan Reyes and Rex Park walking through the api-platform-aws design (EKS + API Gateway + Lambda + RDS + S3).

Tasks

• Replace generic design examples with api-platform-aws
• Use Jordan as the designer, Rex as the collaborator/reviewer
• Cover: opening the design, adding/connecting AWS components, sharing for review
• Update screenshots (Jordan: jordan@orbital-labs.example)
• Link to /cloud/about for cast context

Reference

• Narrative: /cloud/about
• Difficulty: High