HF RL Explorer

Add Excel export support for crawled data

Add Excel export support for crawled data: a task in LegoFlow-SWE (Harbor dataset). Current behavior The MediaCrawler supports CSV, JSON, database, and SQLite storage, but does not recognise "excel" as a valid SAVE DATA OPTION . Choosing it raises ValueError: Invalid save option .

The task

**Current behavior** The MediaCrawler supports CSV, JSON, database, and SQLite storage, but does not recognise `"excel"` as a valid `SAVE_DATA_OPTION`. Choosing it raises `ValueError: Invalid save option`.

Part of Lego-X/LegoFlow-SWE.