[feat] add macOS and mobile resolution controls with disconnect restore

apps/desktop/src/gui/runtime/display_resolution_restoration.h

@@ -0,0 +1,61 @@
+/*
+ * @Author: DI JUNKUN
+ * @Date: 2026-11-11
+ * Copyright (c) 2026 by DI JUNKUN, All Rights Reserved.
+ */
+
+#ifndef _DISPLAY_RESOLUTION_RESTORATION_H_
+#define _DISPLAY_RESOLUTION_RESTORATION_H_
+
+#include <functional>
+#include <map>
+#include <string>
+#include <utility>
+
+#include <display_resolution.h>
+
+namespace crossdesk {
+
+// Application-thread state. Each callback owns the original native display
+// mode, so restoration does not depend on capture still running or slot order.
+class DisplayResolutionRestoration {
+public:
+  using Restore = std::function<bool()>;
+
+  template <typename Capture, typename Change>
+  bool Apply(const std::string &key, Capture capture, Change change) {
+    if (originals_.count(key))
+      return change();
+    if (originals_.size() >= kMaxResolutionDisplays)
+      return false;
+    auto restore = capture();
+    if (!restore)
+      return false;
+    // Save before changing anything, including a failed change whose native
+    // rollback might fail. Subsequent requests never replace this baseline.
+    originals_.emplace(key, std::move(restore));
+    const bool accepted = change();
+    if (!accepted && originals_.at(key)())
+      originals_.erase(key);
+    return accepted;
+  }
+
+  bool RestoreAll() {
+    for (auto it = originals_.begin(); it != originals_.end();) {
+      if (it->second())
+        it = originals_.erase(it);
+      else
+        ++it;
+    }
+    return originals_.empty();
+  }
+
+  bool Empty() const { return originals_.empty(); }
+
+private:
+  std::map<std::string, Restore> originals_;
+};
+
+} // namespace crossdesk
+
+#endif