Suppress global hotkeys while a text field is focused

The save-dialog name field is a focused TMP_InputField, but global discrete
hotkeys kept reading the keyboard every frame, so typing a name like
"Checkers" cycled the pose (C) and shut the server down (K). Add a shared
TypingGuard.IsTyping check (focused TMP/legacy InputField) and short-circuit
the global handlers on it: pose cycle, network dev keys, mode switch, and
paint undo/redo. Movement was already gated out via ControlEnabled.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Assets/Scripts/GameModeManager.cs

@@ -347,6 +347,7 @@ public class GameModeManager : MonoBehaviour
 
     private bool WasSwitchPressed()
     {
+        if (TypingGuard.IsTyping) return false; // don't switch modes while typing in a text field
 #if ENABLE_INPUT_SYSTEM
         return Keyboard.current != null && Keyboard.current[switchKey].wasPressedThisFrame;
 #else