- Changed extract_xlsx_text() to use open_workbook() instead of open_workbook_from_rs()
- Changed extract_xls_text() to use open_workbook() instead of open_workbook_from_rs()
- The calamine 0.26 API uses open_workbook(path) for direct file access
- This matches the pattern used in import_export.rs and vectordb.rs
- Updated AGENTS.md to clarify bots are stored as MinIO buckets
- Added test start.bas with USE KB "sheetlib" for testing KB injection
Root cause: open_workbook_from_rs() is not the correct API for calamine 0.26
Impact: XLSX and XLS files in .gbkb folders were failing to index into vector DB
Fix: Use standard open_workbook() API that accepts file path directly
