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/tutorial.md

@@ -42,7 +42,7 @@ Walk through the implementation.
 ```javascript
 // Example code
 function example() {
-    return 'Hello';
+  return 'Hello';
 }
 ```
 
@@ -53,10 +53,12 @@ How to verify everything works.
 ## Common Issues
 
 ### Issue 1
+
 **Problem:** Description of the problem.
 **Solution:** How to fix it.
 
 ### Issue 2
+
 **Problem:** Description of the problem.
 **Solution:** How to fix it.