fix: apply Codex quota refresh before history scan

[ericweichun]

Summary

• Apply the interim Codex quota refresh on the main thread synchronously before continuing the heavier project history scan.
• Keep the full refresh path asynchronous as before.
• Add test coverage for the interim quota update ordering.

Why

Codex quota loading is fast, but project history refresh can be much heavier because it may scan all-time usage and SQLite logs after a source fingerprint change. Previously the interim Codex quota state was posted to the main thread with waitUntilDone=False, so the background refresh could immediately continue into the heavier history work before the menubar UI had applied the fresh quota. That made Codex usage look stale until a later event or another message caused another refresh.

Test plan

• .venv/bin/python -m pytest tests/test_menubar.py -q
• .venv/bin/ruff check menubar.py tests/test_menubar.py
• .venv/bin/mypy menubar.py tests/test_menubar.py
• uv run pytest tests/