feat(release): publish leech and leech-core to PyPI on tag

[jayhesselberth]

leech is public now, but a tag only produced a GitHub Release. Publishing was
the manual uv publish at the end of .claude/commands/release.md, and
leech-core was never published at all — so pip install "leech[rust]" could
not resolve for anyone outside the workspace.

This publishes both distributions on a v* tag via Trusted Publishing
(OIDC — no API token, no repo secret), following the shape of
escapepod-rs/.github/workflows/release.yml.

Workflow

Three new jobs alongside the existing four:

job	why
check-version	Fails before anything builds if the tag, pyproject.toml, and rust/Cargo.toml disagree. A PyPI upload cannot be replaced, so a wrong version reaching the index is permanent.
test	Runs the suite at the tagged revision. Nothing did before — ci.yml triggers on pushes to main and on PRs, never on a tag.
publish-pypi-core / publish-pypi-leech	Two jobs, not one, so a leech-core failure never blocks leech and each downloads an unambiguous artifact set. Both stay independent of the release job, so a PyPI outage does not cost the GitHub Release.

Permissions narrow from a blanket contents: write to contents: read, with
write on release only and id-token: write on the publish jobs only.

abi3

pyo3 gains abi3-py312 and --find-interpreter is dropped. maturin now emits
one cp312-abi3 wheel per target that loads on CPython 3.12 and every later
3.x, so a new CPython release no longer needs a new leech release to get a
wheel.

📦 Built wheel for abi3 Python ≥ 3.12 to leech_core-0.6.6-cp312-abi3-linux_x86_64.whl

The rust extra is now pinned

rust = ["leech-core==0.6.6"] rather than a bare leech-core. check_rust()
only warns on a mismatch, so for a PyPI install the extra is the only thing
that actually prevents pairing a current leech with a stale extension — the
hazard tests/test_rust_version_pairing.py exists to catch, and the one that
let leech_core sit at 0.3.0 across ten releases.

The version now lives in three files. A new test enforces all three agree, and
check-version enforces they agree with the tag. uv.lock is unaffected: uv
drops the specifier for workspace sources, so the pin appears only in the
published wheel.

Packaging metadata

rust/pyproject.toml carried a name and nothing else, which is a blank PyPI
page — it gains description, README, license, classifiers, and URLs, plus a new
rust/README.md and a rust/LICENSE copy (maturin resolves license-files
against the crate directory, so ../LICENSE is out of reach; escapepod-rs keeps
the same copy for the same reason). Root pyproject.toml moves to the PEP 639
license form and gains [project.urls].

Verification

• Full suite 1019 passed, 27 skipped under the abi3 build, including all of
  test_backend_parity.py, test_parallel_prep.py, and test_prepare_dispatch.py.
• twine check passes on all three artifacts (leech wheel + sdist, leech-core sdist).
• Built leech wheel carries Requires-Dist: leech-core==0.6.6; extra == 'rust',
  License-Expression: MIT, License-File: LICENSE, and no [tool.uv.sources] leakage.
• check-version shell logic exercised against both a matching and a mismatched tag.
• ruff format/lint and ty check src/leech/ clean; uv lock --check current.

Before the first tag

Two pending publishers must be registered at
https://pypi.org/manage/account/publishing/ — both names are currently free.
Without them the publish jobs fail on OIDC.

field	leech	leech-core
Owner	rnabioco	rnabioco
Repository	leech	leech
Workflow	release.yml	release.yml
Environment	pypi-leech	pypi-leech-core

The environments must differ. PyPI identifies a publisher by
(owner, repo, workflow, environment) and enforces a unique constraint on
exactly that tuple — project_name is not part of it (warehouse
_pending_github_oidc_publisher_uc).
Two packages released from one workflow under one environment name collide, and
registering the second fails with "A pending trusted publisher matching this
configuration has already been registered for a different project name."

That message is misleading: it is not a name conflict (a pending publisher never
reserves a name) and needs no admin. The environment is the only field left to
distinguish the two packages, so it carries the package name. The constraint
applies only to pending publishers, which are 1:1 with a project name — once a
project exists its publisher becomes a normal one that several projects may
share — so this is purely a bootstrapping constraint.

Worth tagging a -rc first as an end-to-end rehearsal: check_prerelease
already marks it a GitHub pre-release, and pip install leech will not pick up
a pre-release by default.

Known caveat

The leech-core sdist needs a Rust toolchain and network access to
github.com — escapepod-signal is fetched from git, not crates.io. That affects
anyone off manylinux x86_64/aarch64 (macOS, Windows, musl). It is a property of
the dependency rather than this change, so it is documented in the installation
page rather than worked around.

🤖 Generated with Claude Code