Release v1.6.43

Switched back to top-level document parsing. UltimaDark should now be faster than ever.

I originally moved away from top-level parsing for a reason — there was a bug — but in 2025 I can no longer reproduce or identify it. That may come back to haunt me once users start reporting issues.

That said, a long-standing and previously unfixable bug in the non top-level parsing path is now resolved thanks to this change, which is encouraging.

Cautiously optimistic… let’s ship.