Support up to 500 character file names (#275)

## Summary

- Support up to 500 character file names

## Additional Context

- Fixes #265

src/activities/boot_sleep/SleepActivity.cpp

@@ -49,7 +49,7 @@ void SleepActivity::renderCustomSleepScreen() const {
   auto dir = SdMan.open("/sleep");
   if (dir && dir.isDirectory()) {
     std::vector<std::string> files;
-    char name[128];
+    char name[500];
     // collect all valid BMP files
     for (auto file = dir.openNextFile(); file; file = dir.openNextFile()) {
       if (file.isDirectory()) {

src/activities/reader/FileSelectionActivity.cpp

@@ -39,7 +39,7 @@ void FileSelectionActivity::loadFiles() {
 
   root.rewindDirectory();
 
-  char name[128];
+  char name[500];
   for (auto file = root.openNextFile(); file; file = root.openNextFile()) {
     file.getName(name, sizeof(name));
     if (name[0] == '.' || strcmp(name, "System Volume Information") == 0) {
@@ -123,6 +123,7 @@ void FileSelectionActivity::loop() {
     if (files[selectorIndex].back() == '/') {
       basepath += files[selectorIndex].substr(0, files[selectorIndex].length() - 1);
       loadFiles();
+      selectorIndex = 0;
       updateRequired = true;
     } else {
       onSelect(basepath + files[selectorIndex]);
@@ -137,8 +138,8 @@ void FileSelectionActivity::loop() {
         if (basepath.empty()) basepath = "/";
         loadFiles();
 
-        auto pos = oldPath.find_last_of('/');
-        std::string dirName = oldPath.substr(pos + 1) + "/";
+        const auto pos = oldPath.find_last_of('/');
+        const std::string dirName = oldPath.substr(pos + 1) + "/";
         selectorIndex = findEntry(dirName);
 
         updateRequired = true;
@@ -193,7 +194,7 @@ void FileSelectionActivity::render() const {
 
   const auto pageStartIndex = selectorIndex / PAGE_ITEMS * PAGE_ITEMS;
   renderer.fillRect(0, 60 + (selectorIndex % PAGE_ITEMS) * 30 - 2, pageWidth - 1, 30);
-  for (int i = pageStartIndex; i < files.size() && i < pageStartIndex + PAGE_ITEMS; i++) {
+  for (size_t i = pageStartIndex; i < files.size() && i < pageStartIndex + PAGE_ITEMS; i++) {
     auto item = renderer.truncatedText(UI_10_FONT_ID, files[i].c_str(), renderer.getScreenWidth() - 40);
     renderer.drawText(UI_10_FONT_ID, 20, 60 + (i % PAGE_ITEMS) * 30, item.c_str(), i != selectorIndex);
   }
@@ -201,7 +202,7 @@ void FileSelectionActivity::render() const {
   renderer.displayBuffer();
 }
 
-int FileSelectionActivity::findEntry(const std::string& name) const {
+size_t FileSelectionActivity::findEntry(const std::string& name) const {
   for (size_t i = 0; i < files.size(); i++)
     if (files[i] == name) return i;
   return 0;

src/activities/reader/FileSelectionActivity.h

@@ -14,7 +14,7 @@ class FileSelectionActivity final : public Activity {
   SemaphoreHandle_t renderingMutex = nullptr;
   std::string basepath = "/";
   std::vector<std::string> files;
-  int selectorIndex = 0;
+  size_t selectorIndex = 0;
   bool updateRequired = false;
   const std::function<void(const std::string&)> onSelect;
   const std::function<void()> onGoHome;
@@ -23,7 +23,8 @@ class FileSelectionActivity final : public Activity {
   [[noreturn]] void displayTaskLoop();
   void render() const;
   void loadFiles();
-  int findEntry(const std::string& name) const;
+
+  size_t findEntry(const std::string& name) const;
 
  public:
   explicit FileSelectionActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,