fix(modules): gate keybind toggles on mc.screen == null

Module keybinds used to fire while ChatScreen, PauseScreen or any
other UI was open, so typing a chat message or being in the pause
menu would silently toggle modules whose bind happened to match a
key in the text.

Skip the keybind scan in onKey() unless mc.screen is null, matching
vanilla's "no GUI" gating used elsewhere.

Fixes #19

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/main/java/shit/zen/manager/ModuleManager.java

@@ -191,9 +191,11 @@ public class ModuleManager extends ClientBase {
 
     @EventTarget
     public void onKey(KeyEvent event) {
-        for (Module module : this.moduleMap.values()) {
-            if (module.getKey() != 0 && module.getKey() == event.getKeyCode() && event.isPressed()) {
-                module.toggle();
+        if (mc.screen == null) {
+            for (Module module : this.moduleMap.values()) {
+                if (module.getKey() != 0 && module.getKey() == event.getKeyCode() && event.isPressed()) {
+                    module.toggle();
+                }
             }
         }
     }