Kartonath native Rust client - Linux x86_64 - 20260930-245000

Extract into a new folder. Run ./install-linux-deps.sh if dependencies are
missing, then ./run-kartonath.sh. Keep your existing client as a rollback.
Modern Ubuntu uses libasound2t64; the dependency helper selects it where needed.

This build repairs source lighting in sky-disabled zones such as Surefall.
Titanium retains the last sky colour map while drawing and weather updates are
disabled. The Rust client now preserves that lighting, uses the current clock
to select sun/moon metadata, and leaves server fog unchanged. A fresh login
uses the original DefaultDay asset, matching the original Surefall captures.
No asset files or server database records were modified for this repair.

The first245 candidate was rejected because it advanced hidden sky colours.
The final candidate was checked against original runtime data and with an
explicit121-zone GPU regression. Broader zone transitions, camera/pixel parity,
observer/actor brightness and full Titanium parity remain unfinished.

This is an opt-in build, not an automatic-update or spectator deployment.
Evidence, checksums and current limitations:
https://eq.kaptohmat.com/client-modernization.html
