feat: opt-out of events in the app-server (#11319)

Add `optOutNotificationMethods` in the app-server to opt-out events
based on exact method matching

codex-rs/app-server-protocol/schema/json/codex_app_server_protocol.schemas.json

@@ -5610,6 +5610,16 @@
           "default": false,
           "description": "Opt into receiving experimental API methods and fields.",
           "type": "boolean"
+        },
+        "optOutNotificationMethods": {
+          "description": "Exact notification method names that should be suppressed for this connection (for example `codex/event/session_configured`).",
+          "items": {
+            "type": "string"
+          },
+          "type": [
+            "array",
+            "null"
+          ]
         }
       },
       "type": "object"