Printers report filament_id (e.g., GFA00) but the Bambu Cloud API expects
setting_id format which has an "S" inserted after "GF" (e.g., GFSA00).
- Add _filament_id_to_setting_id() helper function
- Transform IDs before API calls: GFx## -> GFSx##
- User presets (P-prefix) and already-correct IDs unchanged
- Improved warning message to show both original and transformed IDs
