fix: remove over-aggressive WebGL shader compilation pre-check (#236)

The shader-compilation test on a detached test canvas produced false
negatives on Windows (ANGLE backend) and Linux (Mesa), causing the globe
to refuse initialization even when WebGL was fully functional. macOS was
unaffected due to its Metal-backed WebGL implementation.

Replace with a lightweight context-existence check; globe.gl's own
Three.js initialization already handles deeper WebGL failures via the
existing try/catch.

Fixes: #234

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: Brian Keating <brianbruff@users.noreply.github.com>

Author: brianbruff

src/Log4YM.Web/src/plugins/GlobePlugin.tsx

@@ -317,35 +317,21 @@ export function GlobeCore({ hideOverlays, hideCompass }: { hideOverlays?: boolea
   useEffect(() => {
     if (!containerRef.current) return;
 
-    // Thorough WebGL check - test actual shader compilation.
+    // Quick WebGL availability check — only tests for context existence.
+    // The shader-compilation pre-check that was here produced false negatives on
+    // Windows (ANGLE backend) and Linux (Mesa) even when WebGL was fully functional,
+    // preventing the globe from loading on non-macOS platforms.
+    // globe.gl's own Three.js initialization handles deeper WebGL failures via the
+    // try/catch below.
     try {
       const testCanvas = document.createElement('canvas');
-      const gl2 = testCanvas.getContext('webgl2');
-      const gl: WebGLRenderingContext | null = gl2 ??
-        (testCanvas.getContext('webgl') ?? testCanvas.getContext('experimental-webgl') as WebGLRenderingContext | null);
-
+      const gl = testCanvas.getContext('webgl2') ?? testCanvas.getContext('webgl');
       if (!gl) {
         setWebglError('WebGL is not supported in your browser.');
         return;
       }
-
-      const vertexShader = gl.createShader(gl.VERTEX_SHADER);
-      if (!vertexShader) {
-        setWebglError('WebGL shader creation failed.');
-        return;
-      }
-
-      gl.shaderSource(vertexShader, 'void main() { gl_Position = vec4(0.0); }');
-      gl.compileShader(vertexShader);
-
-      if (!gl.getShaderParameter(vertexShader, gl.COMPILE_STATUS)) {
-        setWebglError('WebGL shader compilation failed.');
-        gl.deleteShader(vertexShader);
-        return;
-      }
-      gl.deleteShader(vertexShader);
     } catch (e) {
-      setWebglError('Failed to initialize WebGL.');
+      setWebglError('WebGL is not available in this environment.');
       return;
     }