fix(web-ui): preserve scroll appearance metadata

[bobleer]

Summary

• preserve caller-owned data-bf-component and data-bf-part metadata when product surfaces compose ScrollArea
• retain the design-system defaults when callers do not supply appearance metadata
• update the HooksConfig UI mock for the newly adopted catalog Icon

This repairs the two deterministic test files currently failing on the 1.0.0-explore branch (9 failed tests total) after the ScrollArea/Icon migration.

Testing

• pnpm --dir design-system/packages/ui run build && node --test design-system/packages/ui/tests/scroll-area.test.mjs (4 passed)
• pnpm --dir src/web-ui run test:run src/infrastructure/config/components/HooksConfig.test.tsx src/infrastructure/config/components/common/ConfigPageLayout.test.tsx (14 passed)
• pnpm run check:web:appearance
• git diff --check

Scope

• no visual styling or product behavior changes beyond restoring the existing caller-owned Appearance metadata contract
• no remote workspace, remote control, peer-device, or detached-dispatch behavior changes

AI assistance

AI-assisted change; implementation and focused verification were completed locally.

[bobleer]

Superseded by #2621, which is now merged into and contains the same ScrollArea/Icon contract repairs plus the remaining design-system baseline fixes.

[bobleer]

Superseded by #2621, which is now merged into 1.0.0-explore and contains the same ScrollArea/Icon contract repairs plus the remaining design-system baseline fixes.