Refactor RootLayout and UIHandler for improved structure and functionality

- Updated RootLayout to manage layout initialization and deinitialization more effectively.
- Removed unnecessary dependencies and streamlined event handling for keyboard events.
- Enhanced UIHandler to utilize shared pointers for app descriptors, improving memory management.
- Added methods for showing and hiding navigation elements in RootLayout.
- Introduced textarea widget with instant response by disabling animations.
- Improved error handling and logging throughout the UI components.

main/ui/apps/registry.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include "ui/apps/app.h"
+#include <map>
+#include <string>
+#include "esp_log.h"
+#include <memory>
+
+class AppRegistry {
+public:
+  static AppRegistry& instance() {
+    static AppRegistry registry;
+    return registry;
+  }
+
+  void register_app(std::unique_ptr<AppDescriptor> app_descriptor) {
+    if (app_descriptors_.find(app_descriptor->get_name()) != app_descriptors_.end()) {
+      // App already registered
+      ESP_LOGW("AppRegistry", "App '%s' is already registered", app_descriptor->get_name().c_str());
+      return;
+    }
+    app_descriptors_.emplace(app_descriptor->get_name(), std::move(app_descriptor));
+  }
+
+  size_t size() const {
+    return app_descriptors_.size();
+  }
+
+  // iterators to access registered apps
+  auto begin() { return app_descriptors_.begin(); }
+  auto begin() const { return app_descriptors_.begin(); }
+  auto end() { return app_descriptors_.end(); }
+  auto end() const { return app_descriptors_.end(); }
+
+  // [] operator to get app by name
+  AppDescriptor* operator[](const std::string& name) {
+    auto it = app_descriptors_.find(name);
+    if (it != app_descriptors_.end()) {
+      return it->second.get();
+    }
+    return nullptr;
+  }
+
+private:
+  std::map<std::string, std::unique_ptr<AppDescriptor>> app_descriptors_ = {};
+
+  AppRegistry() = default;
+  // Disable copy and move semantics
+  AppRegistry(const AppRegistry&) = delete;
+  AppRegistry& operator=(const AppRegistry&) = delete;
+  AppRegistry(AppRegistry&&) = delete;
+  AppRegistry& operator=(AppRegistry&&) = delete;
+};