fix: change the google sheet tab name

src/detect_section_selector_masters/sendDiffToGoogleSheets.ts

@@ -48,8 +48,8 @@ async function uploadAllToSheets() {
   const existing = spreadsheet.sheets?.map((s: any) => s.properties?.title || '') || [];
 
   for (const { subdir, file, path } of files) {
-    // Prefix sheet name with directory to distinguish diff vs nav
-    const sheetName = `${subdir}-${file.replace(/\.json$/, '')}`;
+    // Use file name (without extension) as sheetName
+    const sheetName = file.replace(/\.json$/, '');
     if (!existing.includes(sheetName)) {
       // Create new sheet
       await sheets.spreadsheets.batchUpdate({