HASTE V1.1.8.1 — STABLE ANTI-ALIASING HOTFIX

- Rebased on the last user-confirmed working V1.1.7.1 shader source to remove the experimental temporal history pass that coincided with the black/dark scene regression.
- Removed TAA reprojection and subpixel camera jitter; the geometry, shadow and depth paths are unchanged from the working base build.
- Added configurable FXAA spatial edge smoothing in final.fsh.
- Added Anti-aliasing settings with FXAA on for Low and higher profiles, off for Hasteful by default.
- Preserves the previously working Distant Horizons water fix, bloom improvements, terrain compile fix, and water/ice/cloud updates from V1.1.7.1.

FXAA is a stable spatial filter: it reduces jagged edges but cannot fully remove temporal shimmer or Distant Horizons LOD popping. Use Distant Horizons' own LOD anti-aliasing option as well where available.

Validation: archive contents, macro/preprocessor balance, expected buffer path (final reads colortex0), and absence of temporal reprojection/jitter code were checked. An in-game Iris/Distant Horizons render test is still required.
