show_body() now requests the body's Layer-1 cascade output via SimBridge.request_atlas_layers(); the response feeds set_generation_layer1(). The proxy returns Pending on a cache miss and generates in the background (D-225), so the viewer re-requests every 0.5s (20-retry ceiling) until Ready, guarding against stale responses by body_id. Serverless/test mode is a no-op (overlays stay empty). Connected in _ready, torn down in _exit_tree. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>