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

tests/lint-quality.test.js

@@ -0,0 +1,18 @@
+/**
+ * Tests ensuring the codebase has no ESLint warnings.
+ */
+
+const { execSync } = require('child_process');
+const path = require('path');
+
+describe('ESLint quality gate', () => {
+  test('src and tests have no ESLint warnings', () => {
+    const rootDir = path.resolve(__dirname, '..');
+    const result = execSync('npm run lint', {
+      cwd: rootDir,
+      encoding: 'utf8',
+      stdio: ['pipe', 'pipe', 'pipe'],
+    });
+    expect(result).not.toMatch(/warning/);
+  });
+});