fix(sb10): disable FEATURES.highlight to avoid Parcel CJS circular-dep crash
Parcel bundles storybook/internal/preview-api and chunk-SZQXB3JV.js into
a CJS bundle with a circular dependency. During initialization, the chunk's
top-level highlight/preview.ts runs `(_previewApi.addons)?.ready` before the
preview-api chunk's lazy getter has resolved its internal chunk reference.
Result: `TypeError: Cannot read properties of undefined (reading 'addons')`
fires as an unhandled promise rejection and the preview never initializes.
The line is guarded by `globalThis?.FEATURES?.highlight && ...` so setting
features.highlight=false short-circuits the buggy codepath. Trade-off:
disables the highlight feature used by addon-a11y for accessibility-violation
visualization.
This is a workaround; the underlying Parcel + SB10 bundling interaction
should be investigated as a follow-up.