Replace custom ViewportColorCorrector with stageView.py color correction

Remove the custom GL post-process (ViewportColorCorrector) that bypassed
HdxColorCorrectionTask. Instead pass colorCorrectionMode, ocioDisplay,
ocioView, ocioColorSpace, and ocioLook directly to UsdImagingGLRenderParams
and SetColorCorrectionSettings(), delegating correction to Hydra —
the same approach used in usdview's stageView.renderSinglePass().

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/adr/0001-viewport-color-correction.md

@@ -1,6 +1,6 @@
 # ADR 0001 — Custom Viewport Color Correction (sRGB / OCIO)
 
-- **Status:** Accepted
+- **Status:** Superseded (2026-06-30) — replaced by the stageView.py approach (HdxColorCorrectionTask via RenderParams)
 - **Date:** 2026-06-27
 - **Component:** `src/core/UsdSceneRenderer.cpp` (`ViewportColorCorrector`, `ApplyViewportColorCorrection`)
 - **Commit:** `fb1ae9d`
@@ -181,3 +181,14 @@ expected corrected (non-black) image and sRGB is unchanged. Headless automated
 verification is blocked by the stale test-target CMake config (missing USD
 include dirs); restoring those targets would let an OCIO-vs-sRGB center-pixel
 test assert this automatically.
+
+## Supersession Note (2026-06-30)
+
+This ADR is superseded. The custom `ViewportColorCorrector` was removed in favour
+of the approach used in usdview's `stageView.py`: `colorCorrectionMode`,
+`ocioDisplay`, `ocioView`, `ocioColorSpace`, and `ocioLook` are now passed
+directly to `UsdImagingGLRenderParams` and `SetColorCorrectionSettings()`,
+delegating correction to Hydra's `HdxColorCorrectionTask`. The two failure modes
+documented in D1 (black OCIO output, bind-stack corruption) may resurface; the
+try/catch guard around `Render()` remains in place to mitigate the bind-stack
+issue.