Fix tee(0) contract violation, broken apidoc entry point, and doc errors

[virgesmith]

Bug fixes from a full repo review

Code

• tee(n) now raises ValueError for n < 1, as its docstring has always promised. Previously tee(0) returned () and silently discarded the underlying iterator — the existing test even had the pytest.raises assertion commented out. The test now asserts the documented behaviour and that the source iterator is left intact.
• value_counts now behaves like pandas' value_counts (requested follow-up, closes the first item of Enhancement suggestions from repo review #18): reimplemented with Counter.most_common(), so results are ordered most-common-first (ties by first appearance) instead of sorted by key. Items now only need to be hashable rather than orderable (e.g. complex works), and counting is O(n) instead of O(n log n). Breaking change, recorded in relnotes under Unreleased.

Packaging

• Removed the apidoc console script from [project.scripts]. The wheel built by hatchling only packages src/itrx, not src/scripts, so every pip install itrx shipped an apidoc command that immediately fails with ModuleNotFoundError: scripts. It only worked locally because the dev venv uses an editable install. It's a dev-only tool, so rather than shipping the scripts package to PyPI, the entry point is dropped and AGENTS.md now documents uv run python src/scripts/introspect.py.

Doc generator

• generate_apidoc(cls, file) ignored its cls parameter and hardcoded Itr (in getattr, the doc header, and the class docstring). Now uses cls, so output is unchanged for Itr but the function works as its signature advertises.

Documentation

• README license badge pointed at the xenoform package instead of itrx.
• README listed a non-existent accumulated method (should be accumulate).
• Docstring corrections: accumulate documented an initial_value arg (actual name initial) with a "will the the" typo; collect claimed to return "a list"; next_chunk claimed to return a list (returns tuple); skip/skip_while/take_while claimed to return Self/"the iterator itself" (they return new Itr instances); map_dict had a malformed type in its Args.
• Regenerated doc/apidoc.md; added an Unreleased section to relnotes.md.

Verification

All quality gates pass: ruff check, ruff format --check, ty check src, pytest (145 tests, 100% coverage). Also rebuilt the wheel to confirm the stale entry_points.txt no longer ships.

🤖 Generated with Claude Code