v0.4.3

Bug-fix release.

• Fix tokenizer loop condition (operator-precedence bug that made an "other-char" scan always-true)
• Fix code folding: visibleLines now excludes hidden lines so folds actually collapse
• Make EditorViewModel.notifyChange() public and fix a scrollTo arity error so the Perry component typechecks
• Relock native/macos to perry-ffi 0.5.1239

Verified: compiles to a native binary via Perry (examples/perry-test), 430 tests pass, typecheck clean.