Codex app

New features

• You can now fork a conversation from an earlier message, not just the latest turn.
• Added slash commands for switching models and reasoning levels, and made slash commands work in the middle of a draft prompt.
• Added notifications for plan mode questions so it's easier to notice when Codex needs input.

Performance improvements and bug fixes

• Fixed thread handoff and subagent navigation issues across worktrees and the VS Code extension.
• Additional performance improvements and bug fixes.