fix: ctrl-k behavior on macOS (#2052)

* Improve cmd-k / ctrl-k behavior

Use cmd-k on macOS/iOS for search and keep ctrl-k everywhere else.

Fixes a bug where ctrl-k on macOS, which cuts to the end of the line,
was also triggering the search prompt.

* comment submit: cmd-enter (mac) / ctrl-enter (win/linux)

apps/client/src/lib/utils.tsx

@@ -100,6 +100,15 @@ export const normalizeUrl = (url: string): string => {
   return `https://${url}`;
 };
 
+const _isApple = /mac|iphone|ipad|ipod/i.test(navigator.platform ?? "");
+
+/// Cmd key on Apple devices, Ctrl key everywhere else
+export function platformModifierKey(event: KeyboardEvent): boolean {
+  return _isApple ? event.metaKey : event.ctrlKey;
+}
+
+export const platformModifierLabel = _isApple ? "⌘" : "Ctrl";
+
 export function castToBoolean(value: unknown): boolean {
   if (value == null) {
     return false;