Use full lines for Python relative import moves

[tristanmanchester]

Summary

• replace full relative import lines instead of generic from .. prefixes when updating Python move imports
• cover both importer rewrites and self-rewrites in the Python move helper
• add a regression proving from .. import X no longer corrupts sibling imports like from ..utils import Y during apply

Testing

• uv run --with pytest python -m pytest desloppify/languages/python/tests/test_py_move.py

[peteromallet]

Thanks @tristanmanchester. I accepted and applied this change.

Decision: implemented. The review confirmed this was a real Python move-command corruption bug: replacing a broad relative prefix such as from .. could accidentally rewrite sibling imports like from ..utils import helper. I applied the narrow fix so relative from-import moves replace the matched full import line/module portion, added the regression from the PR, and committed it as 1860dd6.

Validation passed:

• PYENV_VERSION=3.11.11 python -m pytest desloppify/languages/python/tests/test_py_move.py -q
• PYENV_VERSION=3.11.11 python -m pytest desloppify/tests/ -q

Closing this PR because the fix has been carried into the local integration branch.

[peteromallet]

Closing after applying the accepted fix locally in commit 1860dd6. Thanks again for the contribution.