Make World Cell resilient and approachable

[JROChub]

What changed

• decoupled Keyxym reconstruction authority from WebGL availability
• added a bounded Canvas 2D inspection renderer for browsers without WebGL
• kept capture, reconstruction, Moments, sealing, evidence, and transfer on the verified v0.26 path when GPU context creation fails
• replaced the first-run wall of internal terminology with a three-step capture workflow
• moved sensor, compute, and cross-device controls behind explicit progressive disclosure
• added desktop and mobile regression coverage for renderer resilience and the new interaction model

Root cause

The Theater constructed THREE.WebGLRenderer before initializing the authoritative runtime. A WebGL context failure therefore rejected the entire v0.26 installation and entered the legacy preview path, even though graphics capability is not reconstruction authority. At the same time, the initial interface presented expert verification and transport controls as primary actions, obscuring the basic capture journey.

Impact

World Cell capture no longer becomes a different, non-authoritative product solely because WebGL is unavailable. New users see a clear capture path, while advanced evidence and device controls remain available on demand.

Validation

• npm test — 13/13 contract suites passed
• npm run build — production TypeScript and Vite build passed
• complete Playwright run — 34 passed, 4 dataset-gated skipped; one legacy exact-label assertion identified and corrected
• focused final Playwright run — authority initialization, authority rejection, no-WebGL resilience, and progressive disclosure all passed
• iPhone WebKit boot and release-module recovery passed
• calibrated RGB-D continuum test produced 14,614 surfels, 50,588 native triangles, and a sealed World Cell