feat: Add extension mechanism for third-party tools in .project format

[Aaravanand00]

Implements extension mechanism for third-party tools in .project format, resolving #125.

Changes

New Types (types.go)

• Extension struct for tool-specific configuration
• ExtensionMetadata struct for author, homepage, repository, license, version

Validation (validator.go)

• Schema version check (requires >= 1.1.0 for extensions)
• Reserved name protection (core fields like name, description, etc. cannot be used as extension keys)
• Extension name format validation (alphanumeric, hyphens, underscores, dots)
• Metadata URL validation

Tests (extensions_test.go)

• Valid extension validation
• Schema version requirement tests
• Reserved name protection tests
• Invalid name format tests
• Metadata URL validation tests
• Backward compatibility tests

Documentation (README.md)

• Added extensions section with usage examples

Example Usage

schema_version: "1.1.0"
extensions:
  scorecard:
    metadata:
      author: "OSSF"
      homepage: "https://securityscorecards.dev"
    config:
      checks:
        - Binary-Artifacts
      threshold: 7.0

[jeefy]

@mlieberman85 Is this close to what you were thinking?

[Copilot]

Pull request overview

This PR implements an extension mechanism that allows third-party tools to store configuration within .project files without conflicts. It introduces the Extension and ExtensionMetadata types, validation logic to enforce schema version requirements (>= 1.1.0) and naming conventions, and comprehensive tests for the new functionality.

Changes:

• Added Extension and ExtensionMetadata structs to support tool-specific configurations
• Implemented validation for extensions including schema version checks, reserved name protection, name format validation, and metadata URL validation
• Added comprehensive test coverage for extension validation scenarios and backward compatibility

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
utilities/dot-project/types.go	Defines new Extension and ExtensionMetadata types with schema version constant
utilities/dot-project/validator.go	Implements validation functions for extensions with reserved name checking and URL validation
utilities/dot-project/extensions_test.go	Provides comprehensive test coverage for extension validation logic
utilities/dot-project/yaml/test-project.yaml	Updates schema version and adds example extension configuration
utilities/dot-project/README.md	Documents the extensions feature with usage examples and naming rules

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[mlieberman85]

@mlieberman85 Is this close to what you were thinking?

I think so. I'm out of the country but should be back on Thursday. I'll try and make a demo of the sorts of things, but I think this PR probably hits most of them.

[Aaravanand00]

Hi @jeefy and @mlieberman85 sir

Copilot Feedback Addressed

Fixed both issues:

1. Semantic version comparison - Replaced string comparison with proper numeric parsing
2. Test coverage - Added edge cases for multi-digit versions (1.10.0 vs 1.2.0)

Also added DCO signatures for compliance. All tests passing

Ready for your review - let me know if any other changes needed.