fix(web): declare card shader UV uniforms

three.js does not auto-declare uniforms added via onBeforeCompile, so the
injected uMapRepeat/uMapOffset were undeclared and the card shader failed
to compile, rendering cards transparent. Prepend the declarations to the
vertex shader.

apps/web/src/components/viewers/cardMaterial.ts

@@ -14,6 +14,14 @@ import * as THREE from 'three';
  * refreshed from `map.matrix` every frame, overwriting any per-material
  * transform we set on the shared texture.
  */
+// Uniforms added via `onBeforeCompile` are not auto-declared by three.js, so
+// they must be declared in the GLSL explicitly (the built-in `mapTransform` is
+// declared in `uv_pars_vertex.glsl.js`).
+const UNIFORM_DECLS = /* glsl */ `
+	uniform vec2 uMapRepeat;
+	uniform vec2 uMapOffset;
+`;
+
 const VERTEX_INJECT = /* glsl */ `
 	#include <uv_vertex>
 	vMapUv = uv * uMapRepeat + uMapOffset;
@@ -36,9 +44,8 @@ export function applyMapTransform(
   material.onBeforeCompile = (shader) => {
     shader.uniforms.uMapRepeat = { value: r };
     shader.uniforms.uMapOffset = { value: o };
-    shader.vertexShader = shader.vertexShader.replace(
-      '#include <uv_vertex>',
-      VERTEX_INJECT,
-    );
+    shader.vertexShader =
+      UNIFORM_DECLS +
+      shader.vertexShader.replace('#include <uv_vertex>', VERTEX_INJECT);
   };
 }