feat: annotate experimental fields in app server protocol

codex-rs/app-server-json-schema/stable/v2/GetAccountParams.json

@@ -0,0 +1,12 @@
+{
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "properties": {
+    "refreshToken": {
+      "default": false,
+      "description": "When `true`, requests a proactive token refresh before returning.\n\nIn managed auth mode this triggers the normal refresh-token flow. In external auth mode this flag is ignored. Clients should refresh tokens themselves and call `account/login/start` with `chatgptAuthTokens`.",
+      "type": "boolean"
+    }
+  },
+  "title": "GetAccountParams",
+  "type": "object"
+}