Desktop app doesn't persist default model (opusplan) across new sessions — requires manual /model opusplan each time

~/.claude/settings.json has "model": "opusplan" set globally (and there's no override in settings.local.json at either user or project level). This is correctly respected by the terminal CLI (claude), which starts each session with opusplan active as expected.

However, in the desktop app (Mac), new sessions instead start with the default model (Sonnet 5, labeled "デフォルト" in the model picker) rather than honoring the persisted model setting from settings.json. I have to manually run /model opusplan every session to restore it, even though it's already configured as the default.

Expected: the desktop app should read and respect the model value in settings.json on session start, the same way the terminal CLI does.