fix: update assistant interface to include context (#1467)

.changeset/easy-bats-end.md

@@ -0,0 +1,5 @@
+---
+"@langchain/langgraph-sdk": patch
+---
+
+add context to assistantBase interface

libs/sdk/src/schema.ts

@@ -108,6 +108,9 @@ export interface AssistantBase {
   /** The assistant config. */
   config: Config;
 
+  /** The assistant context. */
+  context: unknown;
+
   /** The time the assistant was created. */
   created_at: string;