feat: Implement Discord app UI and settings management

- Added MainUI class for displaying voice state, status icon, and buttons.
- Introduced MainUIHandler to manage UI interactions and bridge communication.
- Created SettingsUI for displaying QR code and configuration instructions.
- Implemented SettingsUIHandler to manage settings and web server interactions.
- Developed WebHandler for handling HTTP requests for settings configuration.
- Updated AppRegistry to initialize with the new Discord app descriptor.
- Enhanced InteractionHandler to support keyboard interactions across app switches.
- Updated UIHandler to manage app switching and rendering of app icons.
- Enabled QR code support in LVGL configuration.

main/ui/apps/iotdis/app.cpp

@@ -0,0 +1,131 @@
+#include "ui/apps/iotdis/app.h"
+#include "ui/apps/iotdis/ui/main_handler.h"
+#include "ui/apps/iotdis/ui/settings_handler.h"
+#include "common/system_context.h"
+#include "esp_log.h"
+
+static const char* TAG = "IotDisApp";
+
+// ============================================================================
+// IotDisApp Implementation
+// ============================================================================
+
+IotDisApp::IotDisApp()
+  : main_ui_handler_(nullptr)
+  , settings_ui_handler_(nullptr)
+  , current_page_(Page::MAIN)
+  , setting_handler_(nullptr)
+  , interaction_handler_(nullptr) {
+  setting_handler_ = std::make_unique<SettingHandler>(
+    std::make_unique<NVSStorageHandler>(IotDisApp::NVS_NAMESPACE)
+  );
+}
+
+IotDisApp::~IotDisApp() { }
+
+esp_err_t IotDisApp::init(lv_obj_t* container, InteractionHandler* interaction_handler) {
+  ESP_LOGI(TAG, "Initializing Discord app");
+
+  container_ = container;
+  interaction_handler_ = interaction_handler;
+
+  // Initialize storage
+  setting_handler_->init(nullptr);
+
+  // Load saved settings
+  setting_handler_->load_settings();
+
+  // Create main UI handler
+  main_ui_handler_ = std::make_unique<MainUIHandler>();
+  main_ui_handler_->init(container, interaction_handler_, setting_handler_.get());
+
+  // Register settings button callback
+  main_ui_handler_->register_on_settings_button_clicked(on_settings_button_clicked_static, this);
+
+  current_page_ = Page::MAIN;
+
+  return ESP_OK;
+}
+
+esp_err_t IotDisApp::deinit() {
+  ESP_LOGI(TAG, "Deinitializing Discord app");
+
+  // Clean up UI handlers
+  if (settings_ui_handler_) {
+    settings_ui_handler_->deinit();
+    settings_ui_handler_.reset();
+  }
+
+  if (main_ui_handler_) {
+    main_ui_handler_->deinit();
+    main_ui_handler_.reset();
+  }
+
+  return ESP_OK;
+}
+
+std::string IotDisApp::get_name() const {
+  return "Discord";
+}
+
+bool IotDisApp::on_back_button_pressed() {
+  // If on settings page, go back to main page
+  if (current_page_ == Page::SETTINGS) {
+    // Clean up settings handler
+    if (settings_ui_handler_) {
+      settings_ui_handler_->deinit();
+      settings_ui_handler_.reset();
+    }
+
+    // Reload settings in case they were updated
+    setting_handler_->load_settings();
+
+    // Recreate main UI handler with updated settings
+    if (!main_ui_handler_) {
+      main_ui_handler_ = std::make_unique<MainUIHandler>();
+      main_ui_handler_->init(container_, interaction_handler_, setting_handler_.get());
+      main_ui_handler_->register_on_settings_button_clicked(on_settings_button_clicked_static, this);
+    }
+
+    // Update UI with configuration status
+    main_ui_handler_->update_config_prompt(setting_handler_->is_configured());
+
+    current_page_ = Page::MAIN;
+    return true;
+  }
+
+  // Let system handle back (return to app icons)
+  return false;
+}
+
+// ============================================================================
+// Private Methods
+// ============================================================================
+
+// Settings page with web server and QR code
+void IotDisApp::show_settings_page() {
+  ESP_LOGI(TAG, "Showing settings page");
+
+  // Hide main UI handler
+  if (main_ui_handler_) {
+    main_ui_handler_->deinit();
+    main_ui_handler_.reset();
+  }
+
+  // Create settings UI handler
+  settings_ui_handler_ = std::make_unique<SettingsUIHandler>();
+  settings_ui_handler_->init(container_, interaction_handler_, setting_handler_.get());
+
+  current_page_ = Page::SETTINGS;
+}
+
+// ============================================================================
+// Static Callbacks
+// ============================================================================
+
+void IotDisApp::on_settings_button_clicked_static(lv_event_t* e) {
+  IotDisApp* app = static_cast<IotDisApp*>(lv_event_get_user_data(e));
+  if (app) {
+    app->show_settings_page();
+  }
+}