feat(directory_tree): add excludePatterns support & documentation

[lamemind]

• Update documentation with directory_tree declaration
• Add excludePatterns parameter to DirectoryTreeArgsSchema
• Implement pattern exclusion in buildTree function using minimatch
• Pass excludePatterns through recursive calls
• Support both simple and glob patterns for exclusion
• Maintain consistent behavior with search_files implementation

Description

Motivation and Context

launching directory_tree inside a code project is a pain. adding exclusion pattern is my solution.

How Has This Been Tested?

Tested locally

Breaking Changes

No breaking changes. excludePatterns is empty by default.

Types of changes

• 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 change)
• Documentation update

Checklist

• I have read the MCP Protocol Documentation
• My changes follows MCP security best practices
• I have updated the server's README accordingly
• I have tested this with an LLM client
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have documented all environment variables and configuration options

[cantino]

I'd really like to see excludePatterns added.