test(vtable): cover transpose frozen columns

[fangsmile]

Summary

• add regression coverage proving frozenColCount survives a zero-width mount in transpose mode
• verify frozen scenegraph columns remain fixed after resize and horizontal scrolling
• add an interactive reproduction demo and a none changeset

The production behavior was already corrected by 69e7b58ad; this PR adds the missing coverage for #4111.

Test plan

• npm test -- --runInBand __tests__/options/listTable-frozen.test.ts
• npm run compile
• ESLint, Prettier, commitlint, and git diff --check
• Chrome verification after horizontal navigation (scrollLeft=1057, columns 0-1 remain frozen)

Closes #4111