Add keybind F11 to toggle fullscreen

Records the choice through the same user_value
path as a settings-menu edit.

thirdparty/rexglue-sdk/src/native/ui/rex_app.cpp

@@ -498,6 +498,19 @@ bool ReXApp::OnInitialize() {
   window_->AddListener(this);
   window_->AddInputListener(this, 0);
 
+  // F11 toggles borderless fullscreen (rebindable via the bind_fullscreen
+  // cvar). The change is recorded through the same path as a settings-menu
+  // edit (SetFlagByName -> user_value), so "Save to config" persists it and
+  // the next launch starts in the chosen mode.
+  rex::ui::RegisterBind("bind_fullscreen", "F11", "Toggle fullscreen", [this] {
+    if (!window_) {
+      return;
+    }
+    bool new_fullscreen = !window_->IsFullscreen();
+    window_->SetFullscreen(new_fullscreen);
+    rex::cvar::SetFlagByName("fullscreen", new_fullscreen ? "true" : "false");
+  });
+
   // Attach window to input system so deferred drivers (e.g. MnK) can register
   if (runtime_ && runtime_->input_system()) {
     static_cast<rex::input::InputSystem*>(runtime_->input_system())->AttachWindow(window_.get());
@@ -610,6 +623,9 @@ void ReXApp::OnDestroy() {
   // Notify subclass before cleanup
   OnShutdown();
 
+  // The fullscreen bind's callback captures this - drop it before teardown.
+  rex::ui::UnregisterBind("bind_fullscreen");
+
   // ImGui cleanup (reverse of setup)
   settings_overlay_.reset();
   console_overlay_.reset();

thirdparty/rexglue-sdk/src/ui/keybinds.cpp

@@ -209,6 +209,12 @@ void UnregisterBind(std::string_view name) {
 }
 
 bool ProcessKeyEvent(KeyEvent& e) {
+  // Auto-repeat never fires binds: every bind is a toggle-style action, so a
+  // held key would fire it once per repeat (fullscreen thrash, overlay
+  // flicker). Only the initial down transition counts.
+  if (e.prev_state()) {
+    return false;
+  }
   std::lock_guard lock(g_binds_mutex);
   for (auto& entry : g_binds) {
     if (!entry.callback)