fix: settings persist on font clear, reserve() before push_back, minor (#2519)

src/JsonSettingsIO.cpp

@@ -5,6 +5,7 @@
 #include <Logging.h>
 #include <ObfuscationUtils.h>
 
+#include <algorithm>
 #include <cstring>
 #include <string>
 
@@ -153,10 +154,6 @@ bool JsonSettingsIO::saveSettings(const CrossPointSettings& s, const char* path)
   // Stored as ISO code string ("EN", "DE", ...) for stability across enum reorders.
   doc["language"] = (s.language < getLanguageCount()) ? LANGUAGE_CODES[s.language] : "EN";
 
-  // Language -- managed by LanguageSelectActivity, not in SettingsList.
-  // Stored as ISO code string ("EN", "DE", ...) for stability across enum reorders.
-  doc["language"] = (s.language < getLanguageCount()) ? LANGUAGE_CODES[s.language] : "EN";
-
   String json;
   serializeJson(doc, json);
   return Storage.writeFile(path, json);
@@ -345,6 +342,7 @@ bool JsonSettingsIO::loadRecentBooks(RecentBooksStore& store, const char* json)
 
   store.recentBooks.clear();
   JsonArray arr = doc["books"].as<JsonArray>();
+  store.recentBooks.reserve(std::min(arr.size(), (size_t)10));
   for (JsonObject obj : arr) {
     if (store.getCount() >= 10) break;
     RecentBook book;

src/SdCardFontSystem.cpp

@@ -34,10 +34,12 @@ void SdCardFontSystem::begin(GfxRenderer& renderer) {
       } else {
         LOG_ERR("SDFS", "Failed to load SD font family: %s (clearing)", SETTINGS.sdFontFamilyName);
         SETTINGS.sdFontFamilyName[0] = '\0';
+        SETTINGS.saveToFile();
       }
     } else {
       LOG_DBG("SDFS", "SD font family not found on card: %s (clearing)", SETTINGS.sdFontFamilyName);
       SETTINGS.sdFontFamilyName[0] = '\0';
+      SETTINGS.saveToFile();
     }
   }
 
@@ -76,6 +78,7 @@ void SdCardFontSystem::ensureLoaded(GfxRenderer& renderer) {
       LOG_DBG("SDFS", "SD font family disappeared: %s (clearing)", wantedFamily);
       manager_.unloadAll(renderer);
       SETTINGS.sdFontFamilyName[0] = '\0';
+      SETTINGS.saveToFile();
       return;
     }
     const auto* selected = family->findClosestReaderSize(sizeEnum);
@@ -96,10 +99,12 @@ void SdCardFontSystem::ensureLoaded(GfxRenderer& renderer) {
     } else {
       LOG_ERR("SDFS", "Failed to load SD font family: %s (clearing)", wantedFamily);
       SETTINGS.sdFontFamilyName[0] = '\0';
+      SETTINGS.saveToFile();
     }
   } else {
     LOG_DBG("SDFS", "SD font family not found: %s (clearing)", wantedFamily);
     SETTINGS.sdFontFamilyName[0] = '\0';
+    SETTINGS.saveToFile();
   }
 }
 

src/WifiCredentialStore.cpp

@@ -6,6 +6,8 @@
 #include <ObfuscationUtils.h>
 #include <Serialization.h>
 
+#include <algorithm>
+
 // Initialize the static instance
 WifiCredentialStore WifiCredentialStore::instance;
 
@@ -89,6 +91,7 @@ bool WifiCredentialStore::loadFromBinaryFile() {
   serialization::readPod(file, count);
 
   credentials.clear();
+  credentials.reserve(std::min<size_t>(count, MAX_NETWORKS));
   for (uint8_t i = 0; i < count && i < MAX_NETWORKS; i++) {
     WifiCredential cred;
     serialization::readString(file, cred.ssid);

src/activities/home/FileBrowserActivity.cpp

@@ -336,7 +336,7 @@ std::string getFileName(std::string filename) {
   return filename.substr(0, pos);
 }
 
-std::string getFileExtension(std::string filename) {
+std::string getFileExtension(const std::string& filename) {
   if (filename.back() == '/') {
     return "";
   }