feat: enforce validation environment proof in reviewer reports (Closes #311)

Add assess_validation_environment_proof requiring exact validation command,
working directory, result evidence, and bare-pytest executable/version/venv
proof before reviewer reports can claim validation success.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

tests/test_review_proofs.py

@@ -24,6 +24,7 @@ from review_proofs import (  # noqa: E402
     ISSUE_SELECTION_CONTINUATION_EXPLICIT,
     ISSUE_SELECTION_REPRESENTED_BY_OPEN_PR,
     assess_author_pr_report,
+    assess_validation_environment_proof,
     assess_capability_evidence,
     assess_capability_proof,
     assess_contradictory_no_pr_claim,
@@ -2160,5 +2161,107 @@ class TestCreateIssueFinalReport(unittest.TestCase):
         self.assertTrue(result["downgraded"])
 
 
+class TestValidationEnvironmentProof(unittest.TestCase):
+    """Issue #311: exact validation command and execution environment."""
+
+    ROOT = "/repo/Gitea-Tools/branches/review-pr-280"
+
+    def test_venv_pytest_with_full_report_passes(self):
+        result = assess_validation_environment_proof(
+            report_text=(
+                "Validation command: venv/bin/pytest tests/ --ignore=branches\n"
+                f"Working directory: {self.ROOT}\n"
+                "Result: 1014 passed, 6 skipped"
+            ),
+        )
+        self.assertTrue(result["proven"])
+
+    def test_bare_pytest_without_path_proof_fails(self):
+        result = assess_validation_environment_proof(
+            report_text=(
+                "Validation command: pytest\n"
+                f"Working directory: {self.ROOT}\n"
+                "1014 passed, 6 skipped"
+            ),
+        )
+        self.assertFalse(result["proven"])
+
+    def test_bare_pytest_with_path_and_version_proof_passes(self):
+        result = assess_validation_environment_proof(
+            report_text=(
+                "Validation command: pytest tests/\n"
+                f"Working directory: {self.ROOT}\n"
+                "which pytest: /repo/Gitea-Tools/venv/bin/pytest\n"
+                "pytest --version: pytest 8.3.4\n"
+                "Resolves to the project venv: yes\n"
+                "1014 passed, 6 skipped"
+            ),
+        )
+        self.assertTrue(result["proven"])
+
+    def test_vague_pytest_summary_without_command_fails(self):
+        result = assess_validation_environment_proof(
+            report_text=(
+                f"Working directory: {self.ROOT}\n"
+                "pytest executed inside the worktree: 1014 passed, 6 skipped"
+            ),
+        )
+        self.assertFalse(result["proven"])
+
+    def test_structured_environment_proof_passes(self):
+        result = assess_validation_environment_proof(
+            validation_environment={
+                "command": "pytest tests/",
+                "working_directory": self.ROOT,
+                "which_pytest": "/repo/Gitea-Tools/venv/bin/pytest",
+                "pytest_version": "pytest 8.3.4",
+                "venv_resolved": True,
+                "passed": 1014,
+                "skipped": 6,
+            },
+        )
+        self.assertTrue(result["proven"])
+
+    def test_missing_working_directory_fails(self):
+        result = assess_validation_environment_proof(
+            report_text=(
+                "Validation command: venv/bin/pytest tests/\n"
+                "1014 passed, 6 skipped"
+            ),
+        )
+        self.assertFalse(result["proven"])
+
+    def test_build_final_report_downgrades_missing_environment_proof(self):
+        report = build_final_report(
+            checkout_proof=_good_checkout(),
+            inventory=_good_inventory(),
+            validation=_good_validation(),
+            contamination=_good_contamination(),
+            identity_eligible=True,
+            merge_performed=False,
+            issue_status_verified=True,
+            capability_evidence=_good_capability_evidence(),
+            sweep=_good_sweep(),
+            live_state=_good_live_state(),
+            role_boundary=_good_role_boundary(),
+            review_mutation=_good_review_mutation(),
+            controller_handoff=_good_handoff(),
+            capability_proof=_good_capability_proof(),
+            sweep_proof=_good_secret_sweep(),
+            worktree_proof={
+                "worktree_path": "/repo/branches/review-feat-issue-224",
+                "porcelain_status": "",
+                "pr_scope_files": ["docs/wiki/Repositories.md"],
+                "scratch_used": True,
+            },
+            report_text=(
+                f"Working directory: {self.ROOT}\n"
+                "pytest executed: 1014 passed, 6 skipped"
+            ),
+        )
+        self.assertNotEqual(report["grade"], "A")
+        self.assertFalse(report["validation_environment_proven"])
+
+
 if __name__ == "__main__":
     unittest.main()