fix(tui-v2): repair NameError on exit-boundary replay in _on_stream

[Kailigithub]

Problem

frontends/tuiapp_v2.py:6594 references a local refresh_chrome that the surrounding function _on_stream never receives:

def _on_stream(self, agent_id, task_id, text, done):   # no `refresh_chrome`
    ...
    if s.current_task_id != task_id:
        ...
        if found and agent_id == self.current_id:
            ...
            if refresh_chrome:                            # NameError here
                self._refresh_sidebar()
                self._refresh_topbar()
            self._ensure_spinner()

The function only takes (agent_id, task_id, text, done); refresh_chrome is a parameter of _update_assistant and is not in scope here.

The branch fires whenever exit-boundary replay starts a follow-up task before the original display queue emits its final done — exactly the spinner-forever scenario the comment block warns about. The original if refresh_chrome: guard would always evaluate False (or NameError), so the sidebar/topbar refresh is silently lost in the replay path.

The regular done=True path a few lines below (line ~6603) calls _update_assistant(..., refresh_chrome=True), so the fix mirrors that.

Repro

The included test_issue_6594_tui_v2_stale_replay_nameerror.py exercises the replay path without needing a live Textual app:

$ python3 -m unittest -v test_issue_6594_tui_v2_stale_replay_nameerror
test_done_false_is_a_noop ... ok
test_replay_path_runs_without_name_error ... ok
Ran 2 tests in 1.286s
OK

The test fails on the parent commit with the exact NameError: name refresh_chrome is not defined and passes with this fix.

Verification

• python3 -m ruff check frontends/tuiapp_v2.py --select E9,F63,F7,F82 is clean (8 prior F821 warnings reduced to 0; the 7 List-under-from __future__ import annotations F821s were false positives that pyflakes also flagged — fixed by adding List to the existing from typing import line so typing.get_type_hints on the affected @dataclass and helper functions resolves cleanly).
• python3 -m compileall is clean across the whole repo.
• git diff --check is clean.

Scope

One behaviour change: the replay branch now always refreshes the sidebar and topbar (matching the regular done path), instead of the if refresh_chrome: guard which always evaluated False or raised NameError.

The same fix incidentally resolves a closely-related F821 noise class in this file: from __future__ import annotations is in effect, so the 7 List[...] annotations are stored as strings and do not fail at runtime. @dataclass RenderRow, however, introspects annotations via typing.get_type_hints at class creation, and render_tree return annotation needs List to be in scope if any caller does the same. Adding the import is a 1-line change that matches the codebase other typing-aware modules.

Files

• frontends/tuiapp_v2.py — 1 logic line + 1 import line (8 insertions, 4 deletions)
• test_issue_6594_tui_v2_stale_replay_nameerror.py — new regression test (127 lines)