refactor: use userAgent for OS detection in ShortcutsModal and HelpDropdown

apps/app/src/client/components/ShortcutsModal/ShortcutsModal.tsx

@@ -19,8 +19,8 @@ const ShortcutsModalSubstance = (): React.JSX.Element => {
 
   // Memoize OS-specific class
   const additionalClassByOs = useMemo(() => {
-    const platform = window.navigator.platform.toLowerCase();
-    const isMac = platform.indexOf('mac') > -1;
+    const userAgent = window.navigator.userAgent.toLowerCase();
+    const isMac = userAgent.indexOf('mac') > -1;
     return isMac ? 'mac' : 'win';
   }, []);
 

apps/app/src/client/components/Sidebar/SidebarNav/HelpDropdown.tsx

@@ -25,8 +25,8 @@ export const HelpDropdown: FC = memo(() => {
   }
 
   // add classes to cmd-key by OS
-  const platform = window.navigator.platform.toLowerCase();
-  const isMac = (platform.indexOf('mac') > -1);
+  const userAgent = window.navigator.userAgent.toLowerCase();
+  const isMac = userAgent.indexOf('mac') > -1;
   const os = isMac ? 'mac' : 'win';
 
   // Cloud users see Help, others see Docs