## Why
On a pristine default installation, the provisional composer can appear before
first-login onboarding takes over the terminal.
## What changed
- Detect pristine local installations conservatively, accounting for existing
Codex state, custom homes, access tokens, system configuration, and managed
configuration sources, including macOS managed preferences.
- Keep the composer hidden and ignore draft input until onboarding completes,
while still allowing startup cancellation with `Ctrl-C` or `Ctrl-D`.
- Reveal the configured composer after onboarding for normal new-session
launches; resume and fork pickers retain their existing startup flow.
## Testing
- Cover pristine and existing home layouts, environment credentials, system and
managed configuration, inaccessible state, onboarding input suppression,
cancellation, and the transition to the composer.
GitOrigin-RevId: c1a47ea3ba7c1ff1dd229895c0362b6dd9bfd713
Charlie Marsh
6d97d4c102