Letta MCP Server

## Description Brief description of the changes in this PR ## Type of Change - [ ] 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) - [ ] Documentation update - [ ] Code refactoring - [ ] Performance improvement ## Testing - [ ] I have tested these changes locally - [ ] All existing tests pass - [ ] I have added tests for new functionality ## Checklist - [ ] My code follows the project's code style - [ ] I have updated the documentation accordingly - [ ] I have added/updated relevant comments in the code - [ ] I have checked for any breaking changes - [ ] I have verified all imports work correctly ## Additional Notes Any additional information or context about the PR