Fix: Preserve numeric conversion accuracy in ColorSliderTextFieldConfiguration

[isontheline]

Hey @noppefoxwolf 👋

Thank you so much for your awesome ColorPicker library 🙏

I'm encountering an issue (isontheline/pro.webssh.net#1412) where user can't put some RGB values.

Do you think you can apply this PR on your main branch?
Have you a better way to fix it?

Have a great day ☀️

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Problem

When converting text input back and forth between String ↔︎ Double ↔︎ String, floating-point precision errors caused off-by-one truncations.
Example:

• User enters 96 (percent mode)
• Internal value becomes 0.96
• Converting back with Int(value * 100) yields 95.9999… → truncated to 95

This resulted in unexpected value loss.

Solution

Applied rounding before casting to Int inside all valueToText closures (hex, radius, percent):

let v = (value * scale).rounded()
return "\(Int(v))"

Additionally, values are clamped to the valid ranges (0...255, 0...360, 0...100) to avoid accidental out-of-range results.

Impact

• Fixes off-by-one conversion errors (e.g., 96 remains 96)
• Improves reliability and user trust in the text-to-slider synchronization
• No breaking changes to API

Testing

• Verified with values that previously failed (e.g., 96, 255, 360, 100).
• Round-trip conversion now returns the original value consistently.

[noppefoxwolf]

@isontheline Thank you for your PR.
Looks good to me.