feat(locale): canvi d'idioma al vol amb F7 i persistència

source/core/locale/locale.cpp

@@ -51,7 +51,7 @@ auto Locale::get() -> Locale& {
     return instance_;
 }
 
-void Locale::load(const std::string& file_path) {
+auto Locale::load(const std::string& file_path) -> bool {
     // Normalitza traient prefix "data/" com fa StageLoader: el pack de
     // recursos indexa rutes relatives a `data/`.
     std::string normalized = file_path;
@@ -62,7 +62,7 @@ void Locale::load(const std::string& file_path) {
     std::vector<uint8_t> bytes = Resource::Helper::loadFile(normalized);
     if (bytes.empty()) {
         std::cerr << "[Locale] no s'ha pogut load " << normalized << '\n';
-        return;
+        return false;
     }
 
     try {
@@ -72,11 +72,17 @@ void Locale::load(const std::string& file_path) {
         strings_.clear();
         flatten(yaml, "", strings_);
         std::cout << "[Locale] " << strings_.size() << " traduccions des de " << normalized << '\n';
+        return true;
     } catch (const std::exception& e) {
         std::cerr << "[Locale] error parsejant " << normalized << ": " << e.what() << '\n';
+        return false;
     }
 }
 
+auto Locale::switchTo(const std::string& lang) -> bool {
+    return load("locale/" + lang + ".yaml");
+}
+
 auto Locale::text(const std::string& key) const -> std::string {
     auto it = strings_.find(key);
     if (it != strings_.end()) {