Add release automation script

RELEASE.md

@@ -1,19 +1,72 @@
 # Release Checklist
-The following are the steps to follow to make a new PySCIPOpt release. They should mostly be done in order. 
-- [ ] Check if [scipoptsuite-deploy](https://github.com/scipopt/scipoptsuite-deploy) needs a new release, if a new SCIP version is released for example, or new dependencies (change symmetry dependency, add support for papilo/ parallelization.. etc). And Update release links in `pyproject.toml`
-- [ ] Check if the table in the [documentation](https://pyscipopt.readthedocs.io/en/latest/build.html#building-from-source) needs to be updated. 
-- [ ] Update version number according to semantic versioning [rules](https://semver.org/) in `src/pyscipopt/_version.py` and `setup.py`
-- [ ] Update `CHANGELOG.md`; Change the `Unreleased` to the new version number and add an empty unreleased section.
-- [ ] Create a release candidate on test-pypi by running the workflow “Build wheels” in Actions->build wheels, with these parameters `upload:true, test-pypi:true` 
-- [ ] If the pipeline passes, test the released pip package on test-pypi by running and checking that it works
+
+## Upgrading SCIP
+
+Run `./upgrade_scip.sh` from the `master` branch (use `--dry-run` first to preview without side effects). The script will:
+1. Prompt for SCIP, SoPlex, GCG, and IPOPT versions
+2. Build new binaries via [scipoptsuite-deploy](https://github.com/scipopt/scipoptsuite-deploy) (skipped if a matching release already exists)
+3. Create a branch, update `pyproject.toml`, and open a PR
+
+On the PR:
+- [ ] Fix any API incompatibilities
+- [ ] Get CI green
+- [ ] Update the [compatibility table](https://pyscipopt.readthedocs.io/en/latest/build.html#building-from-source) if needed
+- [ ] Merge into `master`
+
+## Releasing PySCIPOpt
+
+Releases run in two phases from `master`, driven by `./release.sh`. The tag and master push only happen in phase 2, so an aborted release leaves no semantic public trace — just a deletable `release-candidate-vX.Y.Z` branch.
+
+Use `--dry-run` with any command to preview without side effects.
+
+### Phase 1 — start
+
 ```bash
-pip install -i https://test.pypi.org/simple/ PySCIPOpt
+./release.sh
 ```
-- [ ] If it works, release on pypi.org with running the same workflow but with `test-pypi:false`.
-- [ ] Then create a tag with the new version (from the master branch)
+
+Prompts for the version bump (patch/minor/major), updates `_version.py`, `setup.py`, and `CHANGELOG.md`, commits **locally**, pushes the commit to `release-candidate-vX.Y.Z` on origin, and triggers the build-wheels workflow on that branch (uploads to test-pypi). **Master is not pushed, no tag is created.** The script exits as soon as the workflow is dispatched.
+
+To skip the bump prompt (e.g., when test-pypi has already burnt the default next version and you need to jump ahead):
+
 ```bash
-git tag vX.X.X
-git push origin vX.X.X
+./release.sh --version=X.Y.Z
 ```
-- [ ] Then make a github [release](https://github.com/scipopt/PySCIPOpt/releases/new) from this new tag. 
-- [ ] Update the documentation: from readthedocs.io -> Builds -> Build version (latest and stable)
+
+### Manual verification
+
+Once the release-candidate workflow finishes, install from test-pypi and smoke-test:
+
+```bash
+pip install -i https://test.pypi.org/simple/ PySCIPOpt==X.Y.Z
+```
+
+### Phase 2 — finalize or roll back
+
+If the smoke test **passes**:
+
+```bash
+./release.sh --finalize
+```
+
+Checks the release-candidate workflow succeeded, then tags `vX.Y.Z`, pushes master, and deletes the release-candidate branch.
+
+If the smoke test **fails** (or you change your mind):
+
+```bash
+./release.sh --rollback
+```
+
+Deletes the release-candidate branch and resets the local release commit. test-pypi has already burnt the uploaded version string, so the next attempt must use `--version=` to pick a different one.
+
+### After finalize
+
+- [ ] Release to production pypi:
+  ```bash
+  gh workflow run build_wheels.yml --repo scipopt/PySCIPOpt --ref vX.Y.Z -f upload_to_pypi=true -f test_pypi=false
+  ```
+- [ ] Create a GitHub release:
+  ```bash
+  gh release create vX.Y.Z --repo scipopt/PySCIPOpt --title vX.Y.Z --generate-notes
+  ```
+- [ ] Update readthedocs: Builds -> Build version (latest and stable)