fix: Correct process mock and use buttonPress for multi-char commands

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

calculator/test.js

@@ -44,10 +44,8 @@ global.g = {
 
 global.Graphics = {};
 
-// Mock 'process'
-global.process = {
-  env: { HWVERSION: 2 } // Simulate Bangle.js 2
-};
+// Mock Bangle.js-specific process.env properties
+process.env.HWVERSION = 2; // Simulate Bangle.js 2
 
 // Mock 'Bangle'
 global.Bangle = {
@@ -252,37 +250,37 @@ test('Long number with separators', () => {
 
 test('Sine (deg)', () => {
   press('30');
-  press('sin');
+  buttonPress('sin');
   checkDisplay('0.5');
   press('R'); press('R');
   press('90');
-  press('sin');
+  buttonPress('sin');
   checkDisplay('1');
   press('R'); press('R');
   press('180');
-  press('sin');
+  buttonPress('sin');
   checkDisplay('0');
 });
 
 test('Cosine (deg)', () => {
   press('60');
-  press('cos');
+  buttonPress('cos');
   checkDisplay('0.5');
   press('R'); press('R');
   press('0');
-  press('cos');
+  buttonPress('cos');
   checkDisplay('1');
   press('R'); press('R');
   press('90');
-  press('cos');
+  buttonPress('cos');
   checkDisplay('0');
 });
 
 test('Angle mode switch to radians and back', () => {
-    press('angleMode'); // now rad
+    buttonPress('angleMode'); // now rad
     // The buttonPress function doesn't return the state, but we can check the object it modifies
     assert.strictEqual(scientificOperators.angleMode.val, 'rad');
-    press('angleMode'); // back to deg
+    buttonPress('angleMode'); // back to deg
     assert.strictEqual(scientificOperators.angleMode.val, 'deg');
 });