feat: gate reviewer mutations on canonical workflow load proof (Closes #389)

Add gitea_load_review_workflow and in-process session proof required before
gitea_submit_pr_review, gitea_mark_final_review_decision, and gitea_merge_pr.
Capability and runtime context report workflow-load status; stale or missing
proof fails closed with recovery handoff text that forbids approve/merge replay.

tests/test_review_workflow_load.py

@@ -0,0 +1,151 @@
+"""Tests for canonical review workflow load proof (#389)."""
+
+import os
+import sys
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import review_workflow_load
+import mcp_server
+
+
+class TestReviewWorkflowLoadModule(unittest.TestCase):
+    def setUp(self):
+        review_workflow_load.clear_review_workflow_load()
+        mcp_server._save_review_decision_lock(None)
+
+    def test_load_records_hash_and_schema(self):
+        root = str(__import__("pathlib").Path(__file__).resolve().parent.parent)
+        recorded = review_workflow_load.record_review_workflow_load(root)
+        self.assertEqual(
+            recorded["workflow_source"],
+            review_workflow_load.WORKFLOW_REL_PATH,
+        )
+        self.assertEqual(recorded["task_mode"], "review-merge-pr")
+        self.assertRegex(recorded["workflow_hash"], r"^[0-9a-f]{12}$")
+        self.assertEqual(
+            recorded["final_report_schema_path"],
+            review_workflow_load.SCHEMA_REL_PATH,
+        )
+        status = review_workflow_load.workflow_load_status(root)
+        self.assertTrue(status["workflow_load_proof_present"])
+        self.assertTrue(status["workflow_load_valid"])
+
+    def test_stale_session_pid_blocks(self):
+        root = str(__import__("pathlib").Path(__file__).resolve().parent.parent)
+        review_workflow_load.record_review_workflow_load(root)
+        review_workflow_load._REVIEW_WORKFLOW_LOAD["session_pid"] = 0
+        blockers = review_workflow_load.review_workflow_load_blockers(root)
+        self.assertTrue(any("different process" in b for b in blockers))
+
+    def test_prompt_conflict_detected(self):
+        conflict, reasons = review_workflow_load.assess_prompt_conflict(
+            "Run work-issue author implementation only")
+        self.assertTrue(conflict)
+        self.assertTrue(reasons)
+
+
+class TestReviewWorkflowLoadGates(unittest.TestCase):
+    def setUp(self):
+        review_workflow_load.clear_review_workflow_load()
+        mcp_server.init_review_decision_lock("prgs", "review_pr")
+        mcp_server.record_preflight_check("whoami")
+        mcp_server.record_preflight_check("capability", "reviewer")
+
+    def _load_workflow(self):
+        return mcp_server.gitea_load_review_workflow()
+
+    def test_mcp_helper_returns_required_fields(self):
+        res = self._load_workflow()
+        self.assertTrue(res["success"])
+        self.assertTrue(res["loaded"])
+        self.assertIn("workflow_source", res)
+        self.assertIn("workflow_hash", res)
+        self.assertIn("final_report_schema_path", res)
+        self.assertIn("final_report_schema_hash", res)
+
+    def test_mark_final_blocked_without_load(self):
+        res = mcp_server.gitea_mark_final_review_decision(
+            42, "approve", remote="prgs")
+        self.assertFalse(res["marked_ready"])
+        self.assertTrue(any(
+            "gitea_load_review_workflow" in r for r in res["reasons"]))
+        self.assertTrue(any(
+            "approve/merge replay" in r.lower() or "Do not call" in r
+            for r in res["reasons"]))
+
+    def test_submit_review_blocked_without_load(self):
+        with patch("mcp_server.gitea_check_pr_eligibility") as elig:
+            elig.return_value = {
+                "eligible": True,
+                "authenticated_user": "rev",
+                "profile_name": "prgs-reviewer",
+                "pr_author": "author",
+                "head_sha": "abc123",
+                "reasons": [],
+            }
+            res = mcp_server.gitea_submit_pr_review(
+                42,
+                "approve",
+                remote="prgs",
+                final_review_decision_ready=True,
+            )
+        self.assertFalse(res["performed"])
+        self.assertTrue(any(
+            "gitea_load_review_workflow" in r for r in res["reasons"]))
+
+    def test_merge_blocked_without_load(self):
+        res = mcp_server.gitea_merge_pr(
+            42,
+            confirmation="MERGE PR 42",
+            remote="prgs",
+        )
+        self.assertFalse(res["performed"])
+        self.assertTrue(any(
+            "gitea_load_review_workflow" in r for r in res["reasons"]))
+
+    def test_resolve_capability_reports_missing_load(self):
+        with patch.object(mcp_server, "_ensure_matching_profile"):
+            with patch.object(
+                    mcp_server.gitea_config, "is_runtime_switching_enabled",
+                    return_value=False):
+                with patch.object(
+                        mcp_server, "_authenticated_username",
+                        return_value="rev"):
+                    res = mcp_server.gitea_resolve_task_capability(
+                        "review_pr", remote="prgs")
+        proof = res.get("workflow_load_proof") or {}
+        self.assertFalse(proof.get("workflow_load_valid"))
+        self.assertTrue(any(
+            "gitea_load_review_workflow" in g
+            for g in res.get("task_role_guidance") or []))
+
+    def test_init_review_lock_clears_prior_load(self):
+        self._load_workflow()
+        mcp_server.init_review_decision_lock("prgs", "review_pr")
+        blockers = review_workflow_load.review_workflow_load_blockers(
+            str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+        self.assertTrue(blockers)
+
+    def test_dry_run_allowed_without_load(self):
+        with patch("mcp_server.gitea_check_pr_eligibility") as elig:
+            elig.return_value = {
+                "eligible": True,
+                "authenticated_user": "rev",
+                "profile_name": "prgs-reviewer",
+                "pr_author": "author",
+                "head_sha": "abc123",
+                "reasons": [],
+            }
+            res = mcp_server.gitea_dry_run_pr_review(
+                42, "approve", remote="prgs")
+        self.assertNotIn(
+            "gitea_load_review_workflow",
+            " ".join(res.get("reasons") or []),
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()