fix(batch): resolve pandoc path handling and include-subfolders option

- Normalize pandoc command parsing with path.basename() to support bundled binary paths
- Use bundled pandoc binary in convertWithPandoc instead of relying on PATH
- Forward includeSubfolders checkbox state from renderer to main process
- Add pandoc availability check before batch conversion
- Re-enable Start button when batch conversion completes
- Clean up obsolete dist build artifact causing test snapshot warning
- Bump version to 4.4.4

src/templates/changelog.md

@@ -3,18 +3,23 @@
 ## [Unreleased]
 
 ### Added
+
 - New feature
 
 ### Changed
+
 - Updated feature
 
 ### Fixed
+
 - Bug fix
 
 ### Removed
+
 - Removed feature
 
 ## [1.0.0] - {{DATE}}
 
 ### Added
+
 - Initial release