Port the opt-in "High" ambient occlusion quality from the BBFSS fork
(4591e60) onto upstream. graphics_ao_quality (startup-frozen) defaults
to 0 (Regular GTAO, unchanged). 1 selects a three-direction
visibility-bitmask GTAO variant, a depth/normal-aware 5x5 spatial
denoiser, and a full-internal-resolution compute recompute that
replaces the game's bilateral AO upscale output (falls back to the
upscaled half-res HQ result if the upscale draw is not recognised).
Includes settings/looks/overlay wiring, both WPF launchers with 13
localizations, gtao-test, settings-test coverage and engine/docs/hq_ao.md.
Co-authored-by: Copilot App <[email protected]>
