fix(slider): handle precision for values <= 1e-7

Fixes #3852

Description

Fixes an issue where Slider precision breaks for values <= 1e-7 due to improper handling of scientific notation in decimal count calculation.

The previous implementation of getDecimalCount did not correctly handle scientific notation values, leading to incorrect slider step precision calculation.

This update ensures:

• Proper handling of scientific notation (e.g. 1e-7)
• Correct decimal precision calculation for slider steps
• No change in public API or component behavior

This is a non-breaking internal fix with no changes to public API.

Testing

• Verified manually in Storybook with step values <= 1e-7
• Ensured no regression in slider dragging behavior
• All existing tests pass (pnpm test)

Notes

• No additional tests added as existing slider behavior tests already cover precision handling paths.
• No Storybook changes required as UI behavior remains unchanged.