Add Python ecosystem cache support (uv, Poetry, pyenv, pipenv)

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Add Python ecosystem cache support (uv, Poetry, pyenv, pipenv)

ClearDisk already scans pip cache and Conda packages. Adding support for the rest of the Python ecosystem:

Safe to clean (cache only, re-downloads automatically):

• ~/Library/Caches/uv - uv cache (uv is the fastest-growing Python package manager, 80K+ GitHub stars)
• ~/Library/Caches/pypoetry - Poetry cache

Caution (contains installed versions/environments):

• ~/.pyenv/versions - pyenv Python installations
• ~/.local/share/virtualenvs - pipenv virtual environments

Implementation:
Follows the same pattern as the Ruby ecosystem PR (#6). Add entries to:

1. descriptions dictionary
2. devCachePaths() function
3. scanPaths() function

References:

• uv cache docs: https://docs.astral.sh/uv/concepts/cache/
• Poetry cache: https://python-poetry.org/docs/configuration/