Arrow keys work without Fn outside Text Entry

; . , / are arrows on their own unless the foreground App is editing
text (App::textEntryActive); Fn + those keys are arrows everywhere.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

lib/core/src/app.h

@@ -22,6 +22,9 @@ class App {
         return false;
     }
 
+    // True while the App is editing text: the arrow keys then type ; . , / and need Fn to move.
+    virtual bool textEntryActive() const { return false; }
+
     // Called every main-loop pass while in the foreground (e.g. to refresh live values).
     virtual void update(uint32_t nowMs) { (void)nowMs; }