feat: modularize flattener tool into separate components with improved project root detection (#417)

tools/flattener/stats.js

@@ -0,0 +1,30 @@
+function calculateStatistics(aggregatedContent, xmlFileSize) {
+  const { textFiles, binaryFiles, errors } = aggregatedContent;
+
+  const totalTextSize = textFiles.reduce((sum, file) => sum + file.size, 0);
+  const totalBinarySize = binaryFiles.reduce((sum, file) => sum + file.size, 0);
+  const totalSize = totalTextSize + totalBinarySize;
+
+  const totalLines = textFiles.reduce((sum, file) => sum + file.lines, 0);
+
+  const estimatedTokens = Math.ceil(xmlFileSize / 4);
+
+  const formatSize = (bytes) => {
+    if (bytes < 1024) return `${bytes} B`;
+    if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
+    return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
+  };
+
+  return {
+    totalFiles: textFiles.length + binaryFiles.length,
+    textFiles: textFiles.length,
+    binaryFiles: binaryFiles.length,
+    errorFiles: errors.length,
+    totalSize: formatSize(totalSize),
+    xmlSize: formatSize(xmlFileSize),
+    totalLines,
+    estimatedTokens: estimatedTokens.toLocaleString(),
+  };
+}
+
+module.exports = { calculateStatistics };