test: verify delayed prompt injection

Fix pre-existing ty error in action_new_session by typing the sandbox
element as SandboxPolicy | None instead of object.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/hqt/tui/app.py

@@ -12,6 +12,7 @@ from textual.theme import Theme
 from textual.widgets import Footer
 
 from hqt import sandbox
+from hqt.sandbox import SandboxPolicy
 from hqt.config import get_settings
 from hqt.git import worktree
 from hqt.db.engine import ensure_db, get_engine, get_session_factory
@@ -270,7 +271,8 @@ class HqtApp(App):
         project_path = project.path
 
         def on_dismiss(
-            result: tuple[str, str, str | None, str | None, object] | None,
+            result: tuple[str, str, str | None, str | None, SandboxPolicy | None]
+            | None,
         ) -> None:
             if result:
                 harness_name, nickname, model, worktree_branch, sandbox_policy = result

tests/test_tui.py

@@ -1782,7 +1782,9 @@ async def test_schedule_prompt_action_calls_service_and_refreshes():
         with patch.object(app, "notify", side_effect=capture_notify):
             app.action_schedule_prompt()
             await pilot.pause()
-            app.screen.dismiss(("continue", __import__("datetime").timedelta(minutes=30)))
+            app.screen.dismiss(
+                ("continue", __import__("datetime").timedelta(minutes=30))
+            )
             await pilot.pause()
             await app.workers.wait_for_complete()