Modernize packaging + CI: setup.cfg -> pyproject.toml, legacy workflow -> wads uv stub

[thorwhalen]

Summary

Brings videostream2py from the legacy generation (setup.cfg + setup.py +
a hand-rolled ~90-line workflow) onto the current wads standard: a
pyproject.toml single source of truth with a hatchling backend, and a 5-line
ci.yml stub that calls the reusable workflow i2mint/wads/.github/workflows/uv-ci.yml@master.

Merging this PR publishes a release to PyPI. Pushing to master runs the
publish job, which bumps 0.0.2 to the next patch, uploads to PyPI, and pushes
the version bump back. That is intended — but it is a release, not just a config
change.

What changed

Five commits, one concern each:

1. setup.cfg/setup.py -> pyproject.toml (hatchling) + .editorconfig
2. fix: declare the missing opencv-python runtime dependency (see below)
3. CI: legacy workflow -> wads uv reusable-workflow stub
4. docs: add the two missing top-level module docstrings
5. style: ruff format (quote normalization; axblack -> ruff)

Inventory carried across from setup.cfg

setup.cfg	pyproject.toml
name = videostream2py	[project].name
version = 0.0.2	[project].version — deliberately kept at the released PyPI version so CI's auto-bump on merge yields the next patch
description	[project].description
long_description = file:README.md + text/markdown	[project].readme = "README.md"
url	[project.urls].Homepage
license = apache-2.0	license = "Apache-2.0" (SPDX string form; LICENSE kept and now shipped in the wheel's dist-info/licenses/)
install_requires = stream2py	[project].dependencies
packages = find:	hatchling auto-discovery (verified: the built wheel contains both modules)
platforms = any	Operating System :: OS Independent classifier

Nothing was dropped: there were no entry_points/console_scripts, no
package_data, no extras, and no MANIFEST.in/requirements.txt.
include_package_data, zip_safe, description_file, root_url and
display_name are setuptools-/wads-legacy-only keys with no pyproject equivalent.

Filled in what setup.cfg left empty: authors, keywords, classifiers,
requires-python = ">=3.10".

docsrc/conf.py is untouched and still works — epythet's parse_config falls back
to pyproject.toml when setup.cfg is absent.

Latent bug found and fixed

videostream2py/video.py has a module-level import cv2, but opencv-python was
never declared (and stream2py declares no dependencies of its own). A clean
pip install videostream2py therefore produced a package whose only module could
not be imported:

>>> import videostream2py.video
ModuleNotFoundError: No module named 'cv2'

Latent since 0.0.2. Fixed by declaring opencv-python, plus a [tool.wads.ops.libgl]
entry so CI installs libGL on Linux if the runner image ever lacks it (the
opencv-python wheels link against it). On today's runner the check reports
libgl is already installed, so it is a no-op safety net.

testpaths

wads-migrate emits testpaths = ["tests"] unconditionally, and wads CI runs
pytest --doctest-modules with no path argument — so on a repo with no
top-level tests/ dir that setting collects nothing while still reporting green.
Pointed it at the package dir instead. Verified in the branch CI log: the package
is now collected and videostream2py/video.py shows up in the coverage report
(i.e. it is really imported), which is what makes the cv2 gap detectable at all.

Gate results

	priv test-dependents videostream2py
baseline (master)	no-tests — 0 pass, 0 fail, 1 no-tests
final (this branch)	pass — 1 pass, 0 fail, 0 no-tests

Also verified locally: ruff check clean, ruff format --check clean,
uv build produces a correct sdist + wheel.

Branch CI

https://github.com/i2mint/videostream2py/actions/runs/30859318643 — success

Read Configuration    success
Validation (3.10)     success
Validation (3.12)     success
Windows Tests         success
Publish               skipped   (default-branch gated)
Publish GitHub Pages  skipped   (default-branch gated)

Previous master run was red, so this also clears the repo's red-CI finding.

Note: the test matrix widens from 3.10-only to 3.10 + 3.12 + Windows, and
docstring validation moves from pylint C0114 to ruff D100.

Secrets

The old workflow referenced PYPI_USERNAME and PYPI_PASSWORD. The uv CI uses
token-only PyPI auth, so the stub passes only PYPI_PASSWORD; PYPI_USERNAME is
obsolete. No other secrets were referenced, so [tool.wads.ci.env] stays empty.

Deliberately left undone

• No tests. The repo still has zero test files and zero executable doctests
  (the one docstring example needs a camera and is +SKIPed). Out of scope for a
  packaging pass; belongs to a test-coverage pass.
• Package exports nothing — from videostream2py import VideoCapture still
  fails. That is an API change, not a packaging change, so it is filed separately
  as Package exports nothing: from videostream2py import VideoCapture fails #1.

Also done (repo settings, not in this diff)

Homepage set to the docs URL, topics synced from the new keywords, Discussions
enabled — the ecosystem defaults.