11 fix rpy2 depraction of conversion rules

[kgoebler]

closes #11

[Copilot]

Pull Request Overview

This PR fixes rpy2 deprecation warnings by replacing the deprecated activate() conversion methods with the newer localconverter approach. The changes modernize the R interface code to use current rpy2 best practices while maintaining backward compatibility.

• Replaces deprecated numpy2ri.activate() and pandas2ri.activate() with a local converter pattern
• Adds automatic installation of the "drf" R package if not present
• Updates documentation and version number

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
causalAssembly/drf_fitting.py	Modernizes rpy2 conversion methods and adds automatic R package installation
VERSION	Bumps version from 1.2.0 to 1.2.1
README.md	Updates citation and removes manual R package installation requirement

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[Copilot]

Hard-coding the CRAN mirror index to 1 is fragile and may fail if that mirror becomes unavailable. Consider using a more robust approach like utils.chooseCRANmirror(graphics=False) which automatically selects an available mirror, or handle potential failures with error handling.

Suggested change

	utils.chooseCRANmirror(ind=1)
	utils.chooseCRANmirror(graphics=False)

[Copilot]

There's a spelling error in the comment. 'samlpe' should be 'sample'. This was correctly fixed in the code.