chore(canary): record chat_runtime's reviewed module ceiling

loopx/canary/maintainability_ratchet.py

@@ -788,4 +788,24 @@ def render_control_plane_maintainability_report(payload: Mapping[str, Any]) -> s
             )
     for exception_id in payload.get("invalid_exceptions") or []:
         lines.append(f"- invalid exception metadata: {exception_id}")
+    # A module metric budget is settled in the checked-in ledger rather than by
+    # a reviewed exception, so name that file next to the finding: it is the
+    # reviewer-visible edit that decides whether the growth is accepted.
+    if any(
+        str(finding.get("category") or "") == "module_metric_budget"
+        for finding in payload.get("findings") or []
+    ):
+        lines.append(
+            "- module metric debt: refresh the reviewed ceiling in "
+            f"{_module_metric_baseline_name(payload)} for the growth this review accepts"
+        )
     return "\n".join(lines) + "\n"
+
+
+def _module_metric_baseline_name(payload: Mapping[str, Any]) -> str:
+    policy = payload.get("policy")
+    if isinstance(policy, Mapping):
+        declared = str(policy.get("module_metric_baseline_path") or "").strip()
+        if declared:
+            return declared
+    return MODULE_METRIC_BASELINE_PATH.name

loopx/canary/module_metric_baseline.json

@@ -36,9 +36,9 @@
       "lines": 1590
     },
     "loopx/chat_runtime.py": {
-      "any_count": 33,
+      "any_count": 35,
       "dict_any_count": 0,
-      "lines": 1502
+      "lines": 1560
     },
     "loopx/chat_server.py": {
       "any_count": 25,

tests/canary/test_maintainability_ratchet.py

@@ -94,6 +94,55 @@ def test_module_metric_ratchet_rejects_growth_above_checked_in_baseline(
     assert module_metrics(module_path)["any_count"] == 1
 
 
+def test_module_metric_debt_names_the_reviewed_ledger_to_refresh(
+    tmp_path: Path,
+) -> None:
+    """Module metric growth is settled in the checked-in ledger, not by exception."""
+
+    module_path = tmp_path / "loopx" / "sample.py"
+    module_path.parent.mkdir(parents=True)
+    module_path.write_text("\n".join(["# padding"] * 1501), encoding="utf-8")
+
+    payload = evaluate_maintainability_findings(
+        collect_module_metric_findings(tmp_path, tracked_paths={module_path}),
+        reviewed_exceptions={},
+    )
+    rendered = render_control_plane_maintainability_report(
+        {
+            **payload,
+            "policy": {
+                "module_metric_baseline_path": "loopx/canary/module_metric_baseline.json"
+            },
+        }
+    )
+
+    assert payload["ok"] is False
+    assert "module metric debt" in rendered
+    assert "loopx/canary/module_metric_baseline.json" in rendered
+
+
+def test_review_without_module_metric_debt_keeps_the_report_unchanged() -> None:
+    finding = {
+        "id": "compatibility_facade:loopx.sample",
+        "category": "compatibility_facade",
+        "path": "loopx/sample.py",
+    }
+
+    rendered = render_control_plane_maintainability_report(
+        evaluate_maintainability_findings(
+            [finding],
+            reviewed_exceptions={
+                finding["id"]: {
+                    "reason": "A public compatibility window still exists.",
+                    "retirement_plan": "Delete the edge after the window closes.",
+                }
+            },
+        )
+    )
+
+    assert "module metric debt" not in rendered
+
+
 def test_reviewed_exception_lifecycle_rejects_new_debt_and_stale_entries() -> None:
     finding = {
         "id": "dependency_debt:loopx.sample->loopx.presentation",