Move OpenGL texture upload mapping

docs/modernization/roadmap.md

@@ -387,9 +387,10 @@ readback, trace interface validation, and the canonical PanoPainter shader
 catalog now consumed by the legacy OpenGL app initialization path.
 `pp_renderer_gl` now exists as the first OpenGL backend library and owns pure
 OpenGL capability detection for framebuffer fetch, map-buffer alignment, and
-float texture support. The legacy app delegates extension interpretation to
-that backend library, but the existing renderer classes are not yet fully
-behind the renderer interfaces.
+float texture support. It also owns the OpenGL texture upload-type mapping used
+by legacy `Texture2D` and `RTT` creation. The legacy app delegates extension
+and upload-format interpretation to that backend library, but the existing
+renderer classes are not yet fully behind the renderer interfaces.
 
 Implementation tasks:
 
@@ -628,7 +629,8 @@ Results:
 - `pp_renderer_gl_capabilities_tests` passed on default MSVC, vcpkg-headless,
   and Android arm64 configure/build, covering framebuffer fetch, map-buffer
   alignment, desktop GL core float support, GLES float/half-float extensions,
-  and WebGL exclusion behavior.
+  WebGL exclusion behavior, and upload types for RGBA8/RGBA16F/RGBA32F
+  internal formats.
 - PowerShell analyze automation returns JSON summaries and includes the shader
   validation target.
 - `windows-msvc-vcpkg-headless` configured through the Visual Studio bundled