Fix typecheck

Author: jlongster

packages/opencode/test/plugin/github-copilot-models.test.ts

@@ -125,6 +125,9 @@ test("remaps fallback oauth model urls to the enterprise host", async () => {
     project: {} as never,
     directory: "",
     worktree: "",
+    experimental_workspace: {
+      register() {},
+    },
     serverUrl: new URL("https://example.com"),
     $: {} as never,
   })