[jasperblues]

"Prepare release" used to bump only pyproject.toml and uv.lock, so a release left these files naming the old version:

• sample/.drivine/model.json, which records the generator version. python -m drivine.stubs --check, in sample/tests/test_typed_refs_up_to_date.py, compares the whole file. To prove it, I bumped only the build file: the check failed with "Out of date: …/sample/.drivine/model.json".
• sample/poetry.lock: the drivine package entry, in PEP 440 form. Release 0.3.0 #196 missed this one. Running poetry lock after a bump changes exactly that line.
• README.md's "0.2 is an alpha release" line.

What changes

• scripts/release_version.py references VERSION rewrites an explicit REFERENCES list, each entry matched by an anchored pattern. The model file gets the version as written (0.3.0-rc.1). The lock gets it in PEP 440 form (0.3.0rc1), through a stdlib pep440() that a test compares with packaging on 16 versions. The README line has only its MAJOR.MINOR rewritten.
  • Each reference must match exactly once. Every file is checked before any is written, so a reworded line fails loudly and nothing changes.
• prepare-release.yml runs it after uv lock and git adds the files it prints. A new guard fails the run if anything is left unstaged.
• Tests:
  • every reference rewritten, including a prerelease;
  • decoys left alone (drivine-extra, pi-pilgrim at the same version, another library's model file);
  • a missing, doubled or reworded reference fails without writing anything;
  • every .drivine/model.json in the repo is on the list;
  • a repository-consistency test, which runs in CI, checks that every reference names pyproject.toml's version.
• RELEASING.md lists the files and why each one moves.

Verified

• An end-to-end bump to 0.3.0 in a scratch clone, run as the workflow runs it, changes exactly README.md, pyproject.toml, sample/.drivine/model.json, sample/poetry.lock and uv.lock.
• After the bump, the sample's stubs check passes, poetry check --lock passes, and poetry lock changes nothing. So each rewrite matches what the generator and Poetry write. The same holds for 0.3.0-rc.1.
• ruff, pyright and the unit tests pass.
• Reviewed in four passes. The last, an independent one with a pep440() fuzz against packaging, was clean.

Follow-ups, not in this PR

• The sample's check isn't run in CI: ci.yml's pytest covers only tests/. The new consistency test does catch a version mismatch in CI. Running the sample's stubs check in CI too, which needs no database, would catch other drift.
• Move the README's docs into docs/, and keep a short README #223 copies the alpha line into docs/00-introduction.md. When it's rebased, it should add that file to REFERENCES.

This replaces the hand-made release PR #196: Prepare release now makes all of #196's changes, plus sample/poetry.lock.