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/TypingGuard.cs

@@ -0,0 +1,30 @@
+using UnityEngine.EventSystems;
+using TMPro;
+
+/// <summary>
+/// True while the user is editing a focused on-screen text field (e.g. the paint HUD's
+/// "save as" name input). Global gameplay/dev hotkeys consult this so typing a name like
+/// "Checkers" doesn't also fire single-key shortcuts (C = cycle pose, K = shutdown,
+/// the mode-switch key, Ctrl+Z = undo, ...).
+/// </summary>
+public static class TypingGuard
+{
+    /// <summary>A text input field is currently focused and capturing keystrokes.</summary>
+    public static bool IsTyping
+    {
+        get
+        {
+            var es = EventSystem.current;
+            if (!es) return false;
+
+            var go = es.currentSelectedGameObject;
+            if (!go) return false;
+
+            var tmp = go.GetComponent<TMP_InputField>();
+            if (tmp) return tmp.isFocused;
+
+            var legacy = go.GetComponent<UnityEngine.UI.InputField>();
+            return legacy && legacy.isFocused;
+        }
+    }
+}