Keep both atmospheric vertex receivers on retail's exact authored, unnormalized uLights direction in every shadow-gate state while preserving the selected celestial direction for fragment shadow projection and volumetrics. Regenerate the affected SPIR-V and amend IA-24.
Proof adds committed-SPIR-V dataflow checks, parent plain/pipeline source pins, and a real Vulkan mesh+terrain pixel witness owned by Lane=Vulkan.
Mutation first failures (all restored):
1. Restoring the mesh shadow/celestial branch failed CommittedProductionAtmosphericReceivers_KeepAuthoredLightAcrossShadowGate at line 27: expected Pixel 128/128/128/255, actual 0/0/0/255.
2. Restoring the terrain shadow/celestial branch failed the same witness at line 28: expected Pixel 128/128/128/255, actual 0/0/0/255.
3. Normalizing the authored mesh direction failed AssertAuthoredHalfIntensity at line 277: expected 126..129, actual 255.
4. Removing atmospheric_volumetric.frag's celestial xyz use failed ProductionShadowAndVolumetricModules_StillNormalizeTheCelestialProjectionDirection at line 61: Assert.Single found no matching member-5 access.
5. Restoring IA-24's old celestial-base-light claim failed BuiltInAndDeclaredShadowGraphsUseTheSameTypedPriorVisibilitySelector at line 1482: the authored unnormalized uLights sole-base-light assertion was absent.