feat(travel): Implement settings UI and web server for MTR route configuration

- Added MainUIHandler class to manage the main UI and polling for arrival data.
- Introduced SettingsUI class for displaying QR code and configuration options.
- Created SettingsUIHandler to manage settings UI lifecycle and web server interactions.
- Developed WebHandler to handle HTTP requests for MTR route settings, including adding and removing routes.
- Implemented web endpoints for fetching MTR lines, routes, and saving settings.
- Enhanced UI with responsive design for e-ink displays and added error handling for web interactions.

main/external/mtr/arrival.cpp

@@ -11,8 +11,8 @@ StationArrivalInfo::StationArrivalInfo(
   const std::string& train_line_code,
   const std::string& train_station_code
 ) : _status(UNKNOWN_STATUS)
-, _train_line(train_line_code)
-, _train_station(train_station_code) {
+  , _train_line(train_line_code)
+  , _train_station(train_station_code) {
 
   if (!arrival_json) {
     ESP_LOGE(TAG, "arrival_json is null");
@@ -21,6 +21,8 @@ StationArrivalInfo::StationArrivalInfo(
     return;
   }
 
+  ESP_LOGD(TAG, "Parsing arrival JSON for %s-%s", train_line_code.c_str(), train_station_code.c_str());
+
   // Parse status
   cJSON* status_json = cJSON_GetObjectItem(arrival_json, "status");
   if (status_json && cJSON_IsNumber(status_json)) {
@@ -30,7 +32,7 @@ StationArrivalInfo::StationArrivalInfo(
     }
   }
 
-  // TODO: verify the arrival json parsing
+  ESP_LOGD(TAG, "Status: %d, Message: %s", (int)_status, _message.c_str());
 
       // Parse message (if present)
   cJSON* message_json = cJSON_GetObjectItem(arrival_json, "message");