feat(runtime): enforce governed mutation boundaries

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a06ba0-10aa-7ea0-b20a-4f3fac39efe9

tests/test_repository_grant.py

@@ -6,6 +6,7 @@ from pathlib import Path
 
 import pytest
 
+from rein_aharness.metrics import external_metrics_dir
 from rein_aharness.repository_grant import RepositoryGrant, RepositoryGrantError
 from rein_aharness.repository_transaction import RepositoryTransaction
 from rein_aharness.runner import run_task
@@ -242,18 +243,129 @@ def test_taskspec_file_wraps_invalid_repository_grant(tmp_path: Path) -> None:
         TaskSpec.from_file(task_file)
 
 
-def test_runner_refuses_grant_before_adapter_dispatch_or_mutation(tmp_path: Path) -> None:
+def test_runner_accepts_granted_commit_and_keeps_checkout_clean(tmp_path: Path) -> None:
+    repo = _make_repo(tmp_path)
+
+    class Adapter:
+        def execute_prompt(self, prompt: str, config: object):
+            docs = repo / "docs"
+            docs.mkdir()
+            (docs / "result.md").write_text("accepted\n", encoding="utf-8")
+            subprocess.run(["git", "add", "."], cwd=repo, check=True)
+            subprocess.run(
+                [
+                    "git",
+                    "-c",
+                    "user.email=test@example.invalid",
+                    "-c",
+                    "user.name=test",
+                    "commit",
+                    "-qm",
+                    "accepted result",
+                ],
+                cwd=repo,
+                check=True,
+            )
+            from llm_connect.models import LLMResponse
+
+            return LLMResponse(
+                content="done",
+                model="fake",
+                usage={},
+                finish_reason="stop",
+            )
+
+    result = run_task(
+        TaskSpec(
+            title="bounded change",
+            description="update docs",
+            target_repo=repo,
+            repository_grant=RepositoryGrant.from_mapping(_grant()),
+        ),
+        adapter=Adapter(),
+        report_to_hub=False,
+        write_metrics=True,
+    )
+
+    assert result.ok is True
+    assert result.committed is True
+    assert result.transaction is not None
+    assert result.transaction["acceptance"]["accepted"] is True
+    assert result.transaction["acceptance"]["changed_paths"] == ["docs/result.md"]
+    assert result.transaction["repository_grant"]["grant_id"]
+    assert result.transaction["metrics"] == {
+        "storage": "external",
+        "session_id": result.transaction["transaction_id"],
+        "projection_ready": True,
+    }
+    assert _git(repo, "status", "--porcelain=v2") == ""
+    assert not (repo / ".kaizen" / "metrics").exists()
+    metric_path = external_metrics_dir(repo, "coach") / "executions.jsonl"
+    metric_record = json.loads(metric_path.read_text(encoding="utf-8").strip())
+    assert metric_record["session_id"] == result.transaction["transaction_id"]
+
+
+def test_runner_rejects_commit_outside_repository_grant(tmp_path: Path) -> None:
+    repo = _make_repo(tmp_path)
+
+    class Adapter:
+        def execute_prompt(self, prompt: str, config: object):
+            (repo / "UNRELATED.md").write_text("not granted\n", encoding="utf-8")
+            subprocess.run(["git", "add", "."], cwd=repo, check=True)
+            subprocess.run(
+                [
+                    "git",
+                    "-c",
+                    "user.email=test@example.invalid",
+                    "-c",
+                    "user.name=test",
+                    "commit",
+                    "-qm",
+                    "ungranted result",
+                ],
+                cwd=repo,
+                check=True,
+            )
+            from llm_connect.models import LLMResponse
+
+            return LLMResponse(
+                content="done",
+                model="fake",
+                usage={},
+                finish_reason="stop",
+            )
+
+    result = run_task(
+        TaskSpec(
+            title="bounded change",
+            description="update docs",
+            target_repo=repo,
+            repository_grant=RepositoryGrant.from_mapping(_grant()),
+        ),
+        adapter=Adapter(),
+        report_to_hub=False,
+        write_metrics=True,
+    )
+
+    assert result.ok is False
+    assert result.committed is True
+    assert result.reason.startswith("repository acceptance failed: path-not-granted")
+    assert result.transaction is not None
+    assert "acceptance" not in result.transaction
+
+
+def test_runner_refuses_grant_when_durable_metrics_are_disabled(
+    tmp_path: Path,
+) -> None:
     repo = _make_repo(tmp_path)
     called = False
 
     class Adapter:
-        def execute_prompt(self, prompt: str, config: object) -> None:
+        def execute_prompt(self, prompt: str, config: object):
             nonlocal called
             called = True
             raise AssertionError("adapter must not be dispatched")
 
-    head_before = _git(repo, "rev-parse", "HEAD")
-    status_before = _git(repo, "status", "--porcelain=v2")
     result = run_task(
         TaskSpec(
             title="bounded change",
@@ -267,11 +379,69 @@ def test_runner_refuses_grant_before_adapter_dispatch_or_mutation(tmp_path: Path
     )
 
     assert result.ok is False
-    assert result.committed is False
-    assert result.reason.startswith("refused: repository_grant enforcement")
+    assert "require durable external metrics" in result.reason
     assert called is False
-    assert _git(repo, "rev-parse", "HEAD") == head_before
-    assert _git(repo, "status", "--porcelain=v2") == status_before
+
+
+def test_runner_fails_granted_result_when_external_metrics_cannot_persist(
+    tmp_path: Path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    repo = _make_repo(tmp_path)
+
+    class Adapter:
+        def execute_prompt(self, prompt: str, config: object):
+            docs = repo / "docs"
+            docs.mkdir()
+            (docs / "result.md").write_text("accepted\n", encoding="utf-8")
+            subprocess.run(["git", "add", "."], cwd=repo, check=True)
+            subprocess.run(
+                [
+                    "git",
+                    "-c",
+                    "user.email=test@example.invalid",
+                    "-c",
+                    "user.name=test",
+                    "commit",
+                    "-qm",
+                    "accepted result",
+                ],
+                cwd=repo,
+                check=True,
+            )
+            from llm_connect.models import LLMResponse
+
+            return LLMResponse(
+                content="done",
+                model="fake",
+                usage={},
+                finish_reason="stop",
+            )
+
+    def fail_metrics(*args: object, **kwargs: object) -> None:
+        raise OSError("state volume unavailable")
+
+    monkeypatch.setattr(
+        "rein_aharness.runner.metrics.record_external_execution",
+        fail_metrics,
+    )
+    result = run_task(
+        TaskSpec(
+            title="bounded change",
+            description="update docs",
+            target_repo=repo,
+            repository_grant=RepositoryGrant.from_mapping(_grant()),
+        ),
+        adapter=Adapter(),
+        report_to_hub=False,
+        write_metrics=True,
+    )
+
+    assert result.ok is False
+    assert result.reason == "required external metrics persistence failed (OSError)"
+    assert result.transaction is not None
+    assert result.transaction["acceptance"]["accepted"] is True
+    assert _git(repo, "status", "--porcelain=v2") == ""
 
 
 def _git(repo: Path, *args: str) -> str: