fix: align Copilot hook contract

integrations/catalog.schema.json

@@ -148,6 +148,12 @@
                   "fail_closed",
                   "fail_open"
                 ]
+              },
+              "timeout_failure_mode": {
+                "enum": [
+                  "fail_closed",
+                  "fail_open"
+                ]
               }
             }
           },
@@ -332,6 +338,12 @@
                 "fail_closed",
                 "fail_open"
               ]
+            },
+            "timeout_failure_mode": {
+              "enum": [
+                "fail_closed",
+                "fail_open"
+              ]
             }
           }
         },