refactor: Complete redesign of menu interfaces and implementation

[ELDment]

Description

Complete redesign of menu interfaces and implementation.

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Code refactoring (no functional changes)
• Performance improvement
• Test coverage improvement
• Build/CI improvement

Related Issues

Fixes #(issue number)
Closes #85
Related to #85

Changes Made

• Native changes (C++)
• Managed Changes (C#)
• API additions/modifications
• Memory management improvements
• Network handling changes
• SDK updates
• Build system changes

Detailed Changes

List the specific changes made:

Testing

Test Environment

• OS: (e.g., Windows 11, Ubuntu 22.04)
• Game: (e.g., Counter-Strike 2)

Test Cases

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Breaking Changes

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Performance Impact

• No performance impact
• Positive performance impact
• Negative performance impact (explain below)
• Performance impact unknown

Details:

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

Screenshots/Videos (if applicable)

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Additional Notes

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For Maintainers

• Code review completed
• Tests pass
• Ready to merge

[skuzzis]

LGTM

[skuzzis]

Thanks for the big effort put into this PR. <3
We're glad to have such people contributing for a better Source2 Modding Community.