Fix: make toast messages fully opaque

[BrentIO]

Summary

• Removes /50 opacity modifier from dark mode toast backgrounds across both Controller/ui and Hardware-Registration-and-Configuration/ui
• Bumps light mode backgrounds from -50 to -100 tints with matching -300 borders
• Applies to success, warning (amber), and error toast types

Test plan

• Trigger a success toast and confirm it is fully opaque in light and dark mode
• Trigger a warning toast and confirm it is fully opaque in light and dark mode
• Trigger an error toast and confirm it is fully opaque in light and dark mode

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