[codex] Expand extension smoke coverage

[dsafdsaf132]

Summary

• gate raw WEBGL_debug_renderer_info getParameter enums when the extension is filtered out
• make enabledExtensions alias-aware for color-buffer extension aliases
• add smoke coverage for exposed extension constants/runtime paths and a WebGL2 UBO bindBufferRange draw path

Validation

• node --check test/webgl2-smoke.js
• npm run build
• npx --yes node-gyp rebuild
• npm test
• git diff --check