fix: keep stdio targeting on runtime roots

packages/ui/stdio-agent/tests/readline.spec.ts

@@ -16,9 +16,9 @@ function fakeContext(): Context {
   return {
     on: vi.fn(() => vi.fn()),
     effect: vi.fn((callback: () => () => void) => callback()),
-    // The UI seeds its target object from the registry at install; this suite only
+    // The UI seeds its root target from the registry at install; this suite only
     // exercises readline terminal-mode selection, so an empty roster suffices.
-    agents: { list: vi.fn(() => []) },
+    agents: { roots: vi.fn(() => []) },
     userInteraction: { registerProvider: vi.fn(() => vi.fn()) },
   } as unknown as Context
 }