Version Update V1.2.1.0

1. Optimized error 2527.
2. Optimize font display issues.
3. Modify the fan motherboard logic.
4. Resolved issues with Creality Print slicer file preview images not displaying.
5. Optimize silent printing parameter configuration.
6. Add root account information page.
7. Built-in Gcode file update.
8. Modify configuration parameters to optimize first-layer printing.
9. Temperature sensor set to a minimum of -15 degrees Celsius to prevent the machine from reporting errors due to cold conditions in some areas.
10. Optimize the UI interface operation logic.
11. Optimize other known bugs.