fix: Mock FontDylex7x13 module in Node.js test runner

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

calculator/test.js

@@ -53,20 +53,19 @@ global.Bangle = {
 // Mock 'load' (to exit app)
 global.load = () => {};
 
-// Mock 'require' for fonts
-const originalRequire = require;
-global.require = (name) => {
-  if (name === "FontDylex7x13") {
-    return { add: () => {} };
-  }
-  return originalRequire(name);
-};
 // --- End Mock ---
 
 
 // --- Load calculator app ---
 const calculatorCode = fs.readFileSync(path.join(__dirname, 'calculator.app.js'), 'utf8');
-eval(calculatorCode);
+(function(require) {
+  eval(calculatorCode);
+})((name) => {
+  if (name === "FontDylex7x13") {
+    return { add: () => {} };
+  }
+  return require(name);
+});
 // --- End Load ---