Enhances ignore pattern handling with gitignore support

[alexstewartja]

This pull request improves file exclusion logic by leveraging .gitignore files for defining ignore patterns.

Key improvements:

• Replaces custom ignore pattern logic with industry-standard ignore package
• Provides full gitignore compatibility, including negation patterns and nested directories
• Adds comprehensive testing to validate ignore pattern handling and caching
• Improves performance through caching of the ignore matcher

This change removes the hardcoded ignore patterns and relies on .gitignore for more robust and configurable behavior.

[alexstewartja]

@andycufari Conflicts resolved

[andycufari]

Hi @alexstewartja,

Thank you for this comprehensive improvement to our ignore pattern handling! The migration to the ignore package and full gitignore compliance is exactly what we need.

I have a question about the design decision to maintain both .gitignore support and ClaudePoint-level ignore patterns (additionalIgnores).

Current approach in your PR:

• Reads .gitignore patterns
• PLUS maintains additionalIgnores config option
• PLUS always ignores .checkpoints/

Question: What's the reasoning behind having both systems? Most tools use a single ignore mechanism.

Alternative approach:
Would it be simpler to just use .gitignore + the ignore package with minimal additions:
// Always ignore our own directory
ig.add(['.checkpoints/']);

// Use .gitignore for everything else
ig.add(gitignoreContent);

This would:
✅ Follow standard conventions
✅ Reduce configuration complexity
✅ Be more intuitive for users
✅ Still allow custom patterns via .gitignore

Use case question: Are there specific scenarios where additionalIgnores would be needed that can't be handled by adding patterns to .gitignore?

Looking forward to your thoughts on this design decision!

Best,
Andy

[alexstewartja]

Hey @andycufari,

Thanks for taking a look! I'll try to answer your question as concisely as possible.

The preservation of additionalIgnores is to allow for advanced workflows.

A notable example is my use case where I additionally ignore /.git. This keeps the checkpoint archive size small.

My checkpoint and version control workflows differ considerably, hence, advanced usage.

[alexstewartja]

@andycufari You are welcome to test this PRs functionality with:

claude mcp add claudepoint -- npx -y github:alexstewartja/ClaudePoint

[alexstewartja]

@andycufari I see you silently ignored (pun intended) this PR and implemented the ignore npm package anyway. I guess you can close this whenever you choose