fix(TxtReader): Address PR review feedback

- Fix progress update logic: Use lastProgress / 10 != progress / 10
  instead of progressPercent % 2 == 0 to ensure progress updates even
  when percentage jumps odd numbers (matching EpubReaderActivity)

- Fix BW buffer store/restore: Only perform buffer operations when
  textAntiAliasing is enabled (grayscale passes are being rendered)

- Add power button page turn support: Respect the new shortPwrBtn
  PAGE_TURN setting for next page navigation

- Fix word wrap byte tracking: Properly track consumed bytes during
  word wrapping to prevent repeated sections and ensure file end
  is reachable. The previous implementation had incorrect byte offset
  calculations when lines were split across pages.

src/activities/reader/TxtReaderActivity.cpp

@@ -110,6 +110,8 @@ void TxtReaderActivity::loop() {
   const bool prevReleased = mappedInput.wasReleased(MappedInputManager::Button::PageBack) ||
                             mappedInput.wasReleased(MappedInputManager::Button::Left);
   const bool nextReleased = mappedInput.wasReleased(MappedInputManager::Button::PageForward) ||
+                            (SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::PAGE_TURN &&
+                             mappedInput.wasReleased(MappedInputManager::Button::Power)) ||
                             mappedInput.wasReleased(MappedInputManager::Button::Right);
 
   if (!prevReleased && !nextReleased) {
@@ -227,9 +229,9 @@ void TxtReaderActivity::buildPageIndex() {
       pageOffsets.push_back(offset);
     }
 
-    // Update progress bar every 2%
+    // Update progress bar every 10% (matching EpubReaderActivity logic)
     int progressPercent = (offset * 100) / fileSize;
-    if (progressPercent != lastProgressPercent && progressPercent % 2 == 0) {
+    if (lastProgressPercent / 10 != progressPercent / 10) {
       lastProgressPercent = progressPercent;
 
       // Fill progress bar
@@ -272,7 +274,6 @@ bool TxtReaderActivity::loadPageAtOffset(size_t offset, std::vector<std::string>
 
   // Parse lines from buffer
   size_t pos = 0;
-  size_t bytesConsumed = 0;
 
   while (pos < chunkSize && static_cast<int>(outLines.size()) < linesPerPage) {
     // Find end of line
@@ -289,13 +290,18 @@ bool TxtReaderActivity::loadPageAtOffset(size_t offset, std::vector<std::string>
       break;
     }
 
-    // Extract line (without newline)
+    // Calculate the actual length of line content in the buffer (excluding newline)
-    std::string line(reinterpret_cast<char*>(buffer + pos), lineEnd - pos);
+    size_t lineContentLen = lineEnd - pos;
 
-    // Remove carriage return if present
+    // Check for carriage return
-    if (!line.empty() && line.back() == '\r') {
+    bool hasCR = (lineContentLen > 0 && buffer[pos + lineContentLen - 1] == '\r');
-      line.pop_back();
+    size_t displayLen = hasCR ? lineContentLen - 1 : lineContentLen;
-    }
+
+    // Extract line content for display (without CR/LF)
+    std::string line(reinterpret_cast<char*>(buffer + pos), displayLen);
+
+    // Track position within this source line (in bytes from pos)
+    size_t lineBytePos = 0;
 
     // Word wrap if needed
     while (!line.empty() && static_cast<int>(outLines.size()) < linesPerPage) {
@@ -303,6 +309,8 @@ bool TxtReaderActivity::loadPageAtOffset(size_t offset, std::vector<std::string>
 
       if (lineWidth <= viewportWidth) {
         outLines.push_back(line);
+        lineBytePos = displayLen;  // Consumed entire display content
+        line.clear();
         break;
       }
 
@@ -330,30 +338,39 @@ bool TxtReaderActivity::loadPageAtOffset(size_t offset, std::vector<std::string>
       outLines.push_back(line.substr(0, breakPos));
 
       // Skip space at break point
+      size_t skipChars = breakPos;
       if (breakPos < line.length() && line[breakPos] == ' ') {
-        breakPos++;
+        skipChars++;
       }
-      line = line.substr(breakPos);
+      lineBytePos += skipChars;
+      line = line.substr(skipChars);
     }
 
-    // If we still have remaining wrapped text but no room, don't consume this source line
+    // Determine how much of the source buffer we consumed
-    if (!line.empty() && static_cast<int>(outLines.size()) >= linesPerPage) {
+    if (line.empty()) {
+      // Fully consumed this source line, move past the newline
+      pos = lineEnd + 1;
+    } else {
+      // Partially consumed - page is full mid-line
+      // Move pos to where we stopped in the line (NOT past the line)
+      pos = pos + lineBytePos;
       break;
     }
-
-    // Move past the newline
-    bytesConsumed = lineEnd + 1;
-    pos = lineEnd + 1;
   }
 
-  // Handle case where we filled the page mid-line (word wrap)
+  // Ensure we make progress even if calculations go wrong
-  if (bytesConsumed == 0 && !outLines.empty()) {
+  if (pos == 0 && !outLines.empty()) {
-    // We processed some wrapped content, estimate bytes consumed
+    // Fallback: at minimum, consume something to avoid infinite loop
-    // This is approximate - we need to track actual byte positions
+    pos = 1;
-    bytesConsumed = pos;
+  }
+
+  nextOffset = offset + pos;
+
+  // Make sure we don't go past the file
+  if (nextOffset > fileSize) {
+    nextOffset = fileSize;
   }
 
-  nextOffset = offset + (bytesConsumed > 0 ? bytesConsumed : chunkSize);
   free(buffer);
 
   return !outLines.empty();
@@ -455,11 +472,11 @@ void TxtReaderActivity::renderPage() {
     pagesUntilFullRefresh--;
   }
 
+  // Grayscale rendering pass (for anti-aliased fonts)
+  if (SETTINGS.textAntiAliasing) {
     // Save BW buffer for restoration after grayscale pass
     renderer.storeBwBuffer();
 
-  // Grayscale rendering pass (for anti-aliased fonts)
-  if (SETTINGS.textAntiAliasing) {
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
     renderLines();
@@ -472,10 +489,10 @@ void TxtReaderActivity::renderPage() {
 
     renderer.displayGrayBuffer();
     renderer.setRenderMode(GfxRenderer::BW);
-  }
 
     // Restore BW buffer
     renderer.restoreBwBuffer();
+  }
 }
 
 void TxtReaderActivity::renderStatusBar(const int orientedMarginRight, const int orientedMarginBottom,