🐛 [Bug] Clear button deletes entire input in math challenge instead of removing digits one-by-one

[mahendra-918]

Description

Description
The clear button (backspace icon) in the math challenge screen currently resets the entire input to empty. Users expect it to remove the last digit instead of clearing all input.

Steps to Reproduce
Trigger an alarm with a math challenge

Enter multiple digits (e.g., "123")

Tap the backspace (clear) button

Current Behavior:

Entire input is cleared (123 → ``)

Expected Behavior:

Only the last digit is removed (123 → 12)

Screenshots

No response