fix(render): remove duplicate blendMode declaration and add mock activeTexture

src/render/renderer.ts

@@ -268,7 +268,6 @@ export class SpriteRenderer {
   /** Listener references for cleanup. */
   private readonly handleContextLost: (event: Event) => void
   private readonly handleContextRestored: () => void
-  private currentBlendMode: 'normal' | 'additive' = 'normal'
 
   /**
    * @param canvas - the canvas to render into.

tests/missile-skills-113c.test.ts

@@ -956,6 +956,7 @@ describe('Diablo II 1.13c Missile Skills Suite', () => {
         vertexAttribPointer: () => {},
         createTexture: () => ({ id: nextId++ }),
         bindTexture: () => {},
+        activeTexture: () => {},
         texParameteri: () => {},
         pixelStorei: () => {},
         texImage2D: () => {},