diff --git a/lib/Epub/Epub/blocks/TextBlock.h b/lib/Epub/Epub/blocks/TextBlock.h
index 85fdd55a..b528ba03 100644
--- a/lib/Epub/Epub/blocks/TextBlock.h
+++ b/lib/Epub/Epub/blocks/TextBlock.h
@@ -28,6 +28,7 @@ class TextBlock final : public Block {
   void setBlockStyle(const BlockStyle& blockStyle) { this->blockStyle = blockStyle; }
   const BlockStyle& getBlockStyle() const { return blockStyle; }
   const std::vector<std::string>& getWords() const { return words; }
+  const std::vector<int16_t>& getWordXpos() const { return wordXpos; }
   bool isEmpty() override { return words.empty(); }
   size_t wordCount() const { return words.size(); }
   // given a renderer works out where to break the words into lines
diff --git a/lib/GfxRenderer/GfxRenderer.cpp b/lib/GfxRenderer/GfxRenderer.cpp
index 5876e470..8e269eed 100644
--- a/lib/GfxRenderer/GfxRenderer.cpp
+++ b/lib/GfxRenderer/GfxRenderer.cpp
@@ -61,7 +61,7 @@ static inline void rotateCoordinates(const GfxRenderer::Orientation orientation,
   }
 }
 
-enum class TextRotation { None, Rotated90CW };
+enum class TextRotation { None, Rotated90CW, Rotated90CCW };
 
 // Shared glyph rendering logic for normal and rotated text.
 // Coordinate mapping and cursor advance direction are selected at compile time via the template parameter.
@@ -91,6 +91,9 @@ static void renderCharImpl(const GfxRenderer& renderer, GfxRenderer::RenderMode
     if constexpr (rotation == TextRotation::Rotated90CW) {
       outerBase = cursorX + fontData->ascender - top;  // screenX = outerBase + glyphY
       innerBase = cursorY - left;                      // screenY = innerBase - glyphX
+    } else if constexpr (rotation == TextRotation::Rotated90CCW) {
+      outerBase = cursorX + fontData->advanceY - 1 - fontData->ascender + top;  // screenX = outerBase - glyphY
+      innerBase = cursorY + left;                                               // screenY = innerBase + glyphX
     } else {
       outerBase = cursorY - top;   // screenY = outerBase + glyphY
       innerBase = cursorX + left;  // screenX = innerBase + glyphX
@@ -99,12 +102,16 @@ static void renderCharImpl(const GfxRenderer& renderer, GfxRenderer::RenderMode
     if (is2Bit) {
       int pixelPosition = 0;
       for (int glyphY = 0; glyphY < height; glyphY++) {
-        const int outerCoord = outerBase + glyphY;
+        const int outerCoord =
+            (rotation == TextRotation::Rotated90CCW) ? outerBase - glyphY : outerBase + glyphY;
         for (int glyphX = 0; glyphX < width; glyphX++, pixelPosition++) {
           int screenX, screenY;
           if constexpr (rotation == TextRotation::Rotated90CW) {
             screenX = outerCoord;
             screenY = innerBase - glyphX;
+          } else if constexpr (rotation == TextRotation::Rotated90CCW) {
+            screenX = outerCoord;
+            screenY = innerBase + glyphX;
           } else {
             screenX = innerBase + glyphX;
             screenY = outerCoord;
@@ -133,12 +140,16 @@ static void renderCharImpl(const GfxRenderer& renderer, GfxRenderer::RenderMode
     } else {
       int pixelPosition = 0;
       for (int glyphY = 0; glyphY < height; glyphY++) {
-        const int outerCoord = outerBase + glyphY;
+        const int outerCoord =
+            (rotation == TextRotation::Rotated90CCW) ? outerBase - glyphY : outerBase + glyphY;
         for (int glyphX = 0; glyphX < width; glyphX++, pixelPosition++) {
           int screenX, screenY;
           if constexpr (rotation == TextRotation::Rotated90CW) {
             screenX = outerCoord;
             screenY = innerBase - glyphX;
+          } else if constexpr (rotation == TextRotation::Rotated90CCW) {
+            screenX = outerCoord;
+            screenY = innerBase + glyphX;
           } else {
             screenX = innerBase + glyphX;
             screenY = outerCoord;
@@ -1243,6 +1254,64 @@ void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y
   }
 }
 
+void GfxRenderer::drawTextRotated90CCW(const int fontId, const int x, const int y, const char* text, const bool black,
+                                       const EpdFontFamily::Style style) const {
+  if (text == nullptr || *text == '\0') {
+    return;
+  }
+
+  const auto fontIt = fontMap.find(fontId);
+  if (fontIt == fontMap.end()) {
+    LOG_ERR("GFX", "Font %d not found", fontId);
+    return;
+  }
+
+  const auto& font = fontIt->second;
+
+  int32_t yPosFP = fp4::fromPixel(y);
+  int lastBaseY = y;
+  int lastBaseAdvanceFP = 0;
+  int lastBaseTop = 0;
+  constexpr int MIN_COMBINING_GAP_PX = 1;
+
+  uint32_t cp;
+  uint32_t prevCp = 0;
+  while ((cp = utf8NextCodepoint(reinterpret_cast<const uint8_t**>(&text)))) {
+    if (utf8IsCombiningMark(cp)) {
+      const EpdGlyph* combiningGlyph = font.getGlyph(cp, style);
+      int raiseBy = 0;
+      if (combiningGlyph) {
+        const int currentGap = combiningGlyph->top - combiningGlyph->height - lastBaseTop;
+        if (currentGap < MIN_COMBINING_GAP_PX) {
+          raiseBy = MIN_COMBINING_GAP_PX - currentGap;
+        }
+      }
+
+      const int combiningX = x + raiseBy;
+      const int combiningY = lastBaseY + fp4::toPixel(lastBaseAdvanceFP / 2);
+      renderCharImpl<TextRotation::Rotated90CCW>(*this, renderMode, font, cp, combiningX, combiningY, black, style);
+      continue;
+    }
+
+    cp = font.applyLigatures(cp, text, style);
+    if (prevCp != 0) {
+      yPosFP += font.getKerning(prevCp, cp, style);  // add for CCW (opposite of CW)
+    }
+
+    lastBaseY = fp4::toPixel(yPosFP);
+    const EpdGlyph* glyph = font.getGlyph(cp, style);
+
+    lastBaseAdvanceFP = glyph ? glyph->advanceX : 0;
+    lastBaseTop = glyph ? glyph->top : 0;
+
+    renderCharImpl<TextRotation::Rotated90CCW>(*this, renderMode, font, cp, x, lastBaseY, black, style);
+    if (glyph) {
+      yPosFP += glyph->advanceX;  // add for CCW (opposite of CW)
+    }
+    prevCp = cp;
+  }
+}
+
 uint8_t* GfxRenderer::getFrameBuffer() const { return frameBuffer; }
 
 size_t GfxRenderer::getBufferSize() { return HalDisplay::BUFFER_SIZE; }
diff --git a/lib/GfxRenderer/GfxRenderer.h b/lib/GfxRenderer/GfxRenderer.h
index f94fbcbd..3d5fc0a1 100644
--- a/lib/GfxRenderer/GfxRenderer.h
+++ b/lib/GfxRenderer/GfxRenderer.h
@@ -135,9 +135,11 @@ class GfxRenderer {
   std::vector<std::string> wrappedText(int fontId, const char* text, int maxWidth, int maxLines,
                                        EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
 
-  // Helper for drawing rotated text (90 degrees clockwise, for side buttons)
+  // Helpers for drawing rotated text (for side buttons)
   void drawTextRotated90CW(int fontId, int x, int y, const char* text, bool black = true,
                            EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
+  void drawTextRotated90CCW(int fontId, int x, int y, const char* text, bool black = true,
+                            EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
   int getTextHeight(int fontId) const;
 
   // Grayscale functions
diff --git a/lib/Logging/Logging.cpp b/lib/Logging/Logging.cpp
index d7f83606..a8ca529a 100644
--- a/lib/Logging/Logging.cpp
+++ b/lib/Logging/Logging.cpp
@@ -10,7 +10,10 @@ RTC_NOINIT_ATTR char logMessages[MAX_LOG_LINES][MAX_ENTRY_LEN];
 RTC_NOINIT_ATTR size_t logHead = 0;
 
 void addToLogRingBuffer(const char* message) {
-  // Add the message to the ring buffer, overwriting old messages if necessary
+  // RTC_NOINIT memory may contain garbage after flash erase or power loss
+  if (logHead >= MAX_LOG_LINES) {
+    logHead = 0;
+  }
   strncpy(logMessages[logHead], message, MAX_ENTRY_LEN - 1);
   logMessages[logHead][MAX_ENTRY_LEN - 1] = '\0';
   logHead = (logHead + 1) % MAX_LOG_LINES;
diff --git a/open-x4-sdk b/open-x4-sdk
index 91e7e2be..9f76376a 160000
--- a/open-x4-sdk
+++ b/open-x4-sdk
@@ -1 +1 @@
-Subproject commit 91e7e2bef7df514abc7b50aef763d0965abc00a6
+Subproject commit 9f76376a5cc7894cff9ca87bbdd34dab715d8a59
diff --git a/src/RecentBooksStore.cpp b/src/RecentBooksStore.cpp
index f5a2c048..cfe83793 100644
--- a/src/RecentBooksStore.cpp
+++ b/src/RecentBooksStore.cpp
@@ -53,6 +53,15 @@ void RecentBooksStore::updateBook(const std::string& path, const std::string& ti
   }
 }
 
+void RecentBooksStore::removeBook(const std::string& path) {
+  auto it =
+      std::find_if(recentBooks.begin(), recentBooks.end(), [&](const RecentBook& book) { return book.path == path; });
+  if (it != recentBooks.end()) {
+    recentBooks.erase(it);
+    saveToFile();
+  }
+}
+
 bool RecentBooksStore::saveToFile() const {
   Storage.mkdir("/.crosspoint");
   return JsonSettingsIO::saveRecentBooks(*this, RECENT_BOOKS_FILE_JSON);
diff --git a/src/RecentBooksStore.h b/src/RecentBooksStore.h
index 5d98ce83..4d2d4c4f 100644
--- a/src/RecentBooksStore.h
+++ b/src/RecentBooksStore.h
@@ -37,6 +37,8 @@ class RecentBooksStore {
   void updateBook(const std::string& path, const std::string& title, const std::string& author,
                   const std::string& coverBmpPath);
 
+  void removeBook(const std::string& path);
+
   // Get the list of recent books (most recent first)
   const std::vector<RecentBook>& getBooks() const { return recentBooks; }
 
diff --git a/src/activities/reader/DictionaryDefinitionActivity.cpp b/src/activities/reader/DictionaryDefinitionActivity.cpp
index d720488c..ec709894 100644
--- a/src/activities/reader/DictionaryDefinitionActivity.cpp
+++ b/src/activities/reader/DictionaryDefinitionActivity.cpp
@@ -4,7 +4,7 @@
 
 #include <algorithm>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include <cctype>
 #include <cstdlib>
 
diff --git a/src/activities/reader/DictionarySuggestionsActivity.cpp b/src/activities/reader/DictionarySuggestionsActivity.cpp
index 8150675e..8b501e43 100644
--- a/src/activities/reader/DictionarySuggestionsActivity.cpp
+++ b/src/activities/reader/DictionarySuggestionsActivity.cpp
@@ -5,7 +5,7 @@
 #include "DictionaryDefinitionActivity.h"
 #include "HalDisplay.h"
 #include "MappedInputManager.h"
-#include "RenderLock.h"
+#include "activities/RenderLock.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
 #include "util/Dictionary.h"
@@ -56,9 +56,9 @@ void DictionarySuggestionsActivity::loop() {
     startActivityForResult(
         std::make_unique<DictionaryDefinitionActivity>(renderer, mappedInput, selected, definition, readerFontId,
                                                        orientation, true),
-        [this](const ActivityResult& result) {
+        [this](ActivityResult result) {
           if (!result.isCancelled) {
-            setResult(result);
+            setResult(std::move(result));
             finish();
           } else {
             requestUpdate();
diff --git a/src/activities/reader/DictionaryWordSelectActivity.cpp b/src/activities/reader/DictionaryWordSelectActivity.cpp
index dfd0f2ba..ac5631af 100644
--- a/src/activities/reader/DictionaryWordSelectActivity.cpp
+++ b/src/activities/reader/DictionaryWordSelectActivity.cpp
@@ -5,7 +5,7 @@
 #include <algorithm>
 #include <climits>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "CrossPointSettings.h"
 #include "DictionaryDefinitionActivity.h"
 #include "DictionarySuggestionsActivity.h"
@@ -353,9 +353,9 @@ void DictionaryWordSelectActivity::loop() {
       startActivityForResult(
           std::make_unique<DictionaryDefinitionActivity>(renderer, mappedInput, cleaned, definition, fontId, orientation,
                                                          true),
-          [this](const ActivityResult& result) {
+          [this](ActivityResult result) {
             if (!result.isCancelled) {
-              setResult(result);
+              setResult(std::move(result));
               finish();
             } else {
               requestUpdate();
@@ -372,9 +372,9 @@ void DictionaryWordSelectActivity::loop() {
         startActivityForResult(
             std::make_unique<DictionaryDefinitionActivity>(renderer, mappedInput, stem, stemDef, fontId, orientation,
                                                            true),
-            [this](const ActivityResult& result) {
+            [this](ActivityResult result) {
               if (!result.isCancelled) {
-                setResult(result);
+                setResult(std::move(result));
                 finish();
               } else {
                 requestUpdate();
@@ -390,9 +390,9 @@ void DictionaryWordSelectActivity::loop() {
       startActivityForResult(
           std::make_unique<DictionarySuggestionsActivity>(renderer, mappedInput, cleaned, similar, fontId, orientation,
                                                           cachePath),
-          [this](const ActivityResult& result) {
+          [this](ActivityResult result) {
             if (!result.isCancelled) {
-              setResult(result);
+              setResult(std::move(result));
               finish();
             } else {
               requestUpdate();
diff --git a/src/activities/reader/EndOfBookMenuActivity.cpp b/src/activities/reader/EndOfBookMenuActivity.cpp
index bc739ad7..08deed99 100644
--- a/src/activities/reader/EndOfBookMenuActivity.cpp
+++ b/src/activities/reader/EndOfBookMenuActivity.cpp
@@ -3,7 +3,7 @@
 #include <GfxRenderer.h>
 #include <I18n.h>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
diff --git a/src/activities/reader/EpubReaderActivity.cpp b/src/activities/reader/EpubReaderActivity.cpp
index efeb991e..cdb3f3ad 100644
--- a/src/activities/reader/EpubReaderActivity.cpp
+++ b/src/activities/reader/EpubReaderActivity.cpp
@@ -717,7 +717,7 @@ bool EpubReaderActivity::silentIndexNextChapterIfNeeded() {
   marginTop += SETTINGS.screenMargin;
   marginLeft += SETTINGS.screenMargin;
   marginRight += SETTINGS.screenMargin;
-  marginBottom += std::max(SETTINGS.screenMargin, UITheme::getInstance().getStatusBarHeight());
+  marginBottom += std::max(static_cast<int>(SETTINGS.screenMargin), UITheme::getInstance().getStatusBarHeight());
   const uint16_t vpWidth = renderer.getScreenWidth() - marginLeft - marginRight;
   const uint16_t vpHeight = renderer.getScreenHeight() - marginTop - marginBottom;
 
diff --git a/src/activities/reader/EpubReaderBookmarkSelectionActivity.cpp b/src/activities/reader/EpubReaderBookmarkSelectionActivity.cpp
index de3025e6..cfd4622e 100644
--- a/src/activities/reader/EpubReaderBookmarkSelectionActivity.cpp
+++ b/src/activities/reader/EpubReaderBookmarkSelectionActivity.cpp
@@ -2,7 +2,7 @@
 
 #include <GfxRenderer.h>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
diff --git a/src/activities/reader/LookedUpWordsActivity.cpp b/src/activities/reader/LookedUpWordsActivity.cpp
index df2be3fc..7b41c465 100644
--- a/src/activities/reader/LookedUpWordsActivity.cpp
+++ b/src/activities/reader/LookedUpWordsActivity.cpp
@@ -5,7 +5,7 @@
 
 #include <algorithm>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "DictionaryDefinitionActivity.h"
 #include "DictionarySuggestionsActivity.h"
 #include "MappedInputManager.h"
@@ -143,9 +143,9 @@ void LookedUpWordsActivity::loop() {
       startActivityForResult(
           std::make_unique<DictionaryDefinitionActivity>(renderer, mappedInput, headword, definition, readerFontId,
                                                         orientation, true),
-          [this](const ActivityResult& result) {
+          [this](ActivityResult result) {
             if (!result.isCancelled) {
-              setResult(result);
+              setResult(std::move(result));
               finish();
             } else {
               requestUpdate();
@@ -162,9 +162,9 @@ void LookedUpWordsActivity::loop() {
         startActivityForResult(
             std::make_unique<DictionaryDefinitionActivity>(renderer, mappedInput, stem, stemDef, readerFontId,
                                                           orientation, true),
-            [this](const ActivityResult& result) {
+            [this](ActivityResult result) {
               if (!result.isCancelled) {
-                setResult(result);
+                setResult(std::move(result));
                 finish();
               } else {
                 requestUpdate();
@@ -180,9 +180,9 @@ void LookedUpWordsActivity::loop() {
       startActivityForResult(
           std::make_unique<DictionarySuggestionsActivity>(renderer, mappedInput, headword, similar, readerFontId,
                                                          orientation, cachePath),
-          [this](const ActivityResult& result) {
+          [this](ActivityResult result) {
             if (!result.isCancelled) {
-              setResult(result);
+              setResult(std::move(result));
               finish();
             } else {
               requestUpdate();
diff --git a/src/activities/settings/NtpSyncActivity.cpp b/src/activities/settings/NtpSyncActivity.cpp
index bb7d7f85..5856bfb3 100644
--- a/src/activities/settings/NtpSyncActivity.cpp
+++ b/src/activities/settings/NtpSyncActivity.cpp
@@ -5,7 +5,7 @@
 #include <Logging.h>
 #include <WiFi.h>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "CrossPointSettings.h"
 #include "MappedInputManager.h"
 #include "activities/network/WifiSelectionActivity.h"
diff --git a/src/activities/settings/OpdsServerListActivity.cpp b/src/activities/settings/OpdsServerListActivity.cpp
index 16c26a5b..63c61d49 100644
--- a/src/activities/settings/OpdsServerListActivity.cpp
+++ b/src/activities/settings/OpdsServerListActivity.cpp
@@ -3,7 +3,7 @@
 #include <GfxRenderer.h>
 #include <I18n.h>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "MappedInputManager.h"
 #include "OpdsServerStore.h"
 #include "OpdsSettingsActivity.h"
diff --git a/src/activities/settings/OpdsSettingsActivity.cpp b/src/activities/settings/OpdsSettingsActivity.cpp
index ec54bcc5..0b1250c3 100644
--- a/src/activities/settings/OpdsSettingsActivity.cpp
+++ b/src/activities/settings/OpdsSettingsActivity.cpp
@@ -6,7 +6,7 @@
 #include <cstring>
 #include <string>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "MappedInputManager.h"
 #include "OpdsServerStore.h"
 #include "activities/util/DirectoryPickerActivity.h"
diff --git a/src/activities/util/DirectoryPickerActivity.cpp b/src/activities/util/DirectoryPickerActivity.cpp
index e1ce0040..4b7d0522 100644
--- a/src/activities/util/DirectoryPickerActivity.cpp
+++ b/src/activities/util/DirectoryPickerActivity.cpp
@@ -5,7 +5,7 @@
 
 #include <cstring>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
diff --git a/src/activities/util/NumericStepperActivity.cpp b/src/activities/util/NumericStepperActivity.cpp
index 023ac974..c6f5732a 100644
--- a/src/activities/util/NumericStepperActivity.cpp
+++ b/src/activities/util/NumericStepperActivity.cpp
@@ -6,7 +6,7 @@
 #include <algorithm>
 #include <cstdio>
 
-#include "ActivityResult.h"
+#include "activities/ActivityResult.h"
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
diff --git a/src/util/Dictionary.h b/src/util/Dictionary.h
index b7bf89d8..6c3cd43c 100644
--- a/src/util/Dictionary.h
+++ b/src/util/Dictionary.h
@@ -1,11 +1,11 @@
 #pragma once
+#include <HalStorage.h>
+
 #include <cstdint>
 #include <functional>
 #include <string>
 #include <vector>
 
-class FsFile;
-
 class Dictionary {
  public:
   static bool exists();
diff --git a/src/util/StringUtils.cpp b/src/util/StringUtils.cpp
index 81be07ee..5ad2902f 100644
--- a/src/util/StringUtils.cpp
+++ b/src/util/StringUtils.cpp
@@ -2,6 +2,10 @@
 
 #include <Utf8.h>
 
+#include <algorithm>
+#include <cctype>
+#include <cstring>
+
 namespace StringUtils {
 
 std::string sanitizeFilename(const std::string& name, size_t maxBytes) {
@@ -43,4 +47,48 @@ std::string sanitizeFilename(const std::string& name, size_t maxBytes) {
   return result.empty() ? "book" : result;
 }
 
+bool checkFileExtension(const std::string& fileName, const char* extension) {
+  const size_t extLen = strlen(extension);
+  if (fileName.length() < extLen) return false;
+  const std::string tail = fileName.substr(fileName.length() - extLen);
+  for (size_t i = 0; i < extLen; i++) {
+    if (tolower(static_cast<unsigned char>(tail[i])) != tolower(static_cast<unsigned char>(extension[i]))) return false;
+  }
+  return true;
+}
+
+void sortFileList(std::vector<std::string>& entries) {
+  std::sort(entries.begin(), entries.end(), [](const std::string& a, const std::string& b) {
+    bool isDir1 = !a.empty() && a.back() == '/';
+    bool isDir2 = !b.empty() && b.back() == '/';
+    if (isDir1 != isDir2) return isDir1;
+
+    const char* s1 = a.c_str();
+    const char* s2 = b.c_str();
+
+    while (*s1 && *s2) {
+      if (isdigit(*s1) && isdigit(*s2)) {
+        while (*s1 == '0') s1++;
+        while (*s2 == '0') s2++;
+        int len1 = 0, len2 = 0;
+        while (isdigit(s1[len1])) len1++;
+        while (isdigit(s2[len2])) len2++;
+        if (len1 != len2) return len1 < len2;
+        for (int i = 0; i < len1; i++) {
+          if (s1[i] != s2[i]) return s1[i] < s2[i];
+        }
+        s1 += len1;
+        s2 += len2;
+      } else {
+        char c1 = tolower(*s1);
+        char c2 = tolower(*s2);
+        if (c1 != c2) return c1 < c2;
+        s1++;
+        s2++;
+      }
+    }
+    return *s1 == 0 && *s2 != 0;
+  });
+}
+
 }  // namespace StringUtils
diff --git a/src/util/StringUtils.h b/src/util/StringUtils.h
index 1fa6cc01..25f2a1db 100644
--- a/src/util/StringUtils.h
+++ b/src/util/StringUtils.h
@@ -1,6 +1,7 @@
 #pragma once
 
 #include <string>
+#include <vector>
 
 namespace StringUtils {
 
@@ -11,4 +12,15 @@ namespace StringUtils {
  */
 std::string sanitizeFilename(const std::string& name, size_t maxBytes = 100);
 
+/**
+ * Case-insensitive file extension check.
+ */
+bool checkFileExtension(const std::string& fileName, const char* extension);
+
+/**
+ * Sort a file/directory list with directories first, using case-insensitive natural sort.
+ * Directory entries are identified by a trailing '/'.
+ */
+void sortFileList(std::vector<std::string>& entries);
+
 }  // namespace StringUtils