v1.0.1

Major release for the multi-package monorepo migration.

Highlights:

• repository reorganized into package-local projects under packages/*
• each package now has its own pyproject.toml, ruff.toml, pytest.ini, tests/, and Makefile
• root make check now delegates into package-local make check
• shared DTOs such as WordPair and ScoredWordPair now live only in nl_processing.core.models
• legacy re-exports for shared models were removed
• aggregate root build was updated to package the multi-root layout correctly

Breaking changes:

• shared model imports must use nl_processing.core.models
• old single-tree repo layout and root test layout are no longer the source of truth