Keep SPM valuation out of program benefits and isolate simulation policy

.github/release-lock.md

@@ -41,13 +41,34 @@ the same prerequisite, and `Publish` checks its own committed checkout again
 before installation or build. Model environments use locked synchronization;
 subsequent commands use that environment without synchronizing again.
 
+The PR `CandidateWheel` matrix starts from the reviewed head in two separate
+clean checkouts. Both run the actual release version-bump helper; the `rc1`
+entry appends `rc1` to that computed next version before both perform the
+root-only lock refresh. Each uses the same Ubuntu version, Python, uv, locked
+development environment, and `make` build as `Publish`. Each uploads its
+unpublished wheel and `release-build/receipt.json`; the job has read-only
+repository access and no publication step. The receipt rejects changed or
+untracked policy source, checks the wheel's version and backend, and records source, lock, tool, and
+wheel identities. Download the `release-wheel-rc1-<head SHA>` and
+`release-wheel-final-<head SHA>` artifacts to qualify their actual bytes.
+A change to the head or changelog fragments requires a new candidate; the
+candidate does not reserve a registry version.
+GitHub updates its hosted Ubuntu images even within `ubuntu-24.04`, so receipts
+also record `ImageOS` and `ImageVersion` for release-environment comparison.
+
+`pyproject.toml` pins Hatchling and its complete non-optional dependency closure
+because `python -m build` creates an isolated backend environment outside the
+runtime lock. Both builds use those same pins and the frontend version in
+`uv.lock`. `Publish` verifies its own receipt before publishing. Registry wheel
+comparison and downstream qualification remain separate release checks.
+
 `ReleaseLockTests` has no dependency on a model job or the country lock check.
 It uses only the Python standard library and uv, so it can test the guard while
 the country dependency registry is incomplete:
 
 ```sh
-python -m unittest discover -s .github/tests -p test_release_lock.py -v
-RELEASE_LOCK_REAL_UV=1 python -m unittest discover -s .github/tests -p test_release_lock.py -v
+python -m unittest discover -s .github/tests -p 'test_release_*.py' -v
+RELEASE_LOCK_REAL_UV=1 python -m unittest discover -s .github/tests -p 'test_release_*.py' -v
 ```
 
 The opt-in probe creates an isolated, minimal project with a standard PyPI

.github/release_build.py

@@ -0,0 +1,161 @@
+"""Verify clean policy source and record a locally built release wheel.
+
+The PR matrix can prepare either candidate using the actual release bump helper.
+Both candidates and Publish record a receipt after the same make command.
+This script never resolves dependencies or publishes.
+"""
+
+from __future__ import annotations
+
+import hashlib
+from importlib.metadata import version
+import json
+import os
+from pathlib import Path
+import platform
+import re
+import subprocess
+import sys
+import tomllib
+from zipfile import ZipFile
+
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def prepare_candidate(root: Path, kind: str) -> None:
+    """Use the actual release helper, optionally preparing its rc1 counterpart."""
+    if kind not in {"rc1", "final"}:
+        raise ValueError("Candidate kind must be rc1 or final")
+    subprocess.run(
+        [sys.executable, str(root / ".github/bump_version.py")], cwd=root, check=True
+    )
+    if kind == "rc1":
+        path = root / "pyproject.toml"
+        project = path.read_text()
+        final_version = tomllib.loads(project)["project"]["version"]
+        prepared, count = re.subn(
+            rf'^(version\s*=\s*"){re.escape(final_version)}("\s*)$',
+            rf"\g<1>{final_version}rc1\g<2>",
+            project,
+            flags=re.MULTILINE,
+        )
+        if count != 1:
+            raise ValueError("Expected exactly one release version assignment")
+        path.write_text(prepared)
+
+
+def _sha256(path: Path) -> str:
+    return hashlib.sha256(path.read_bytes()).hexdigest()
+
+
+def checked_build_requirements(project: dict) -> dict[str, str]:
+    """Require exact pins for every declared isolated-build requirement."""
+    if project["build-system"]["build-backend"] != "hatchling.build":
+        raise ValueError("Release backend must match the reviewed Hatchling build")
+    requirements = {}
+    for requirement in project["build-system"]["requires"]:
+        match = re.fullmatch(r"([A-Za-z0-9_.-]+)==([0-9][A-Za-z0-9_.]*)", requirement)
+        if match is None or match[1] in requirements:
+            raise ValueError("Release build requirements must be unique exact pins")
+        requirements[match[1]] = match[2]
+    if "hatchling" not in requirements:
+        raise ValueError("Release build requires an exact Hatchling pin")
+    return requirements
+
+
+def wheel_identity(
+    path: Path, *, expected_version: str, hatchling_version: str
+) -> dict:
+    """Bind wheel bytes to the requested release and its declared backend."""
+    with ZipFile(path) as wheel:
+        bad_member = wheel.testzip()
+        if bad_member is not None:
+            raise ValueError(f"Invalid wheel member: {bad_member}")
+        infos = [name for name in wheel.namelist() if name.endswith(".dist-info/WHEEL")]
+        if len(infos) != 1:
+            raise ValueError("Expected exactly one wheel metadata directory")
+        prefix = infos[0].removesuffix("WHEEL")
+        metadata = wheel.read(prefix + "METADATA").decode()
+        wheel_metadata = wheel.read(infos[0]).decode()
+        if re.findall(r"^Version: (.+)$", metadata, re.MULTILINE) != [expected_version]:
+            raise ValueError("Wheel version differs from the prepared release")
+        if re.findall(r"^Generator: (.+)$", wheel_metadata, re.MULTILINE) != [
+            f"hatchling {hatchling_version}"
+        ]:
+            raise ValueError("Wheel generator differs from the pinned backend")
+    return {
+        "filename": path.name,
+        "sha256": _sha256(path),
+        "size_bytes": path.stat().st_size,
+    }
+
+
+def write_build_receipt(root: Path = ROOT) -> Path:
+    """Fail if tests changed package inputs, then retain only public build facts."""
+    subprocess.run(
+        ["git", "diff", "--exit-code", "HEAD", "--", "policyengine_us"],
+        cwd=root,
+        check=True,
+    )
+    untracked = subprocess.check_output(
+        ["git", "ls-files", "--others", "--exclude-standard", "--", "policyengine_us"],
+        cwd=root,
+    )
+    if untracked.strip():
+        raise ValueError("Untracked policy source would enter the release wheel")
+    project = tomllib.loads((root / "pyproject.toml").read_text())
+    lock = tomllib.loads((root / "uv.lock").read_text())
+    requirements = checked_build_requirements(project)
+    frontend = version("build")
+    locked_frontends = [
+        item["version"] for item in lock["package"] if item["name"] == "build"
+    ]
+    if locked_frontends != [frontend]:
+        raise ValueError("Installed build frontend differs from the registry lock")
+    wheels = sorted((root / "dist").glob("*.whl"))
+    if len(wheels) != 1:
+        raise ValueError("Expected exactly one freshly built release wheel")
+    receipt = {
+        "source_head": subprocess.check_output(
+            ["git", "rev-parse", "HEAD"], cwd=root, text=True
+        ).strip(),
+        "policy_tree": subprocess.check_output(
+            ["git", "rev-parse", "HEAD:policyengine_us"], cwd=root, text=True
+        ).strip(),
+        "policy_source_matches_head": True,
+        "prepared_version": project["project"]["version"],
+        "pyproject_sha256": _sha256(root / "pyproject.toml"),
+        "uv_lock_sha256": _sha256(root / "uv.lock"),
+        "python": platform.python_version(),
+        "platform": platform.system(),
+        "machine": platform.machine(),
+        "runner_image": {
+            "os": os.environ.get("ImageOS"),
+            "version": os.environ.get("ImageVersion"),
+        },
+        "uv": subprocess.check_output(["uv", "--version"], text=True).strip(),
+        "frontend": {"name": "build", "version": frontend},
+        "isolated_build_requirements": requirements,
+        "wheel": wheel_identity(
+            wheels[0],
+            expected_version=project["project"]["version"],
+            hatchling_version=requirements["hatchling"],
+        ),
+    }
+    output = root / "release-build" / "receipt.json"
+    output.parent.mkdir(exist_ok=True)
+    output.write_text(json.dumps(receipt, indent=2, sort_keys=True) + "\n")
+    return output
+
+
+if __name__ == "__main__":
+    import argparse
+
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--prepare", choices=("rc1", "final"))
+    args = parser.parse_args()
+    if args.prepare:
+        prepare_candidate(ROOT, args.prepare)
+    else:
+        print(write_build_receipt().read_text(), end="")