feat(bar): add independent widget radius controls and optional plugin radius override

[tibssy]

Pull Request

Motivation

This PR introduces a dedicated bar widget radius setting so bar capsule roundness can be tuned independently from global container and input radius. It also migrates core bar capsule/widget surfaces to bar specific radius, making the behavior consistent and easier to reason about. For plugins, it adds an optional global override toggle so users can choose whether plugin widgets should follow bar radius, with live updates and no shell restart required.

Type of Change

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• Bug fix
• New feature
• Breaking change
• Refactoring

Related Issue

• Closes #(issue number) (if any)

Testing

Describe how you tested your changes and mark the relevant items.

• Tested on niri
• Tested on Hyprland
• Tested on sway
• Tested with different bar positions and density settings
• Tested at different interface scaling values
• Tested with multiple monitors (if applicable)

Screenshots / Videos

recording_20260401_021757.mp4

Checklist

• Code follows project style guidelines
• Self-reviewed my code
• No new warnings or errors
• Documentation or comments updated (if relevant)

Additional Notes

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