Make steer stable by default

[aibrahim-oai]

Promotes the Steer feature from Experimental to Stable and enables it by default.

What is Steer mode?

Steer mode changes how message submission works in the TUI:

• With Steer enabled (new default):

  • Enter submits messages immediately, even when a task is running
  • Tab queues messages when a task is running (allows building up a queue)

• With Steer disabled (old behavior):

  • Enter queues messages when a task is running
  • This preserves the previous "queue while a task is running" behavior

How Steer vs Queue work

The key difference is in the submission behavior:

1. Steer mode (steer_enabled = true):

   • Enter → InputResult::Submitted → sends immediately via submit_user_message()
   • Tab → InputResult::Queued → queues via queue_user_message() if a task is running
   • This gives users direct control: Enter for immediate submission, Tab for queuing

2. Queue mode (steer_enabled = false, previous default):

   • Enter → InputResult::Queued → always queues when a task is running
   • Tab → InputResult::Queued → queues when a task is running
   • This preserves the original behavior where Enter respects the running task queue

Implementation details

The behavior is controlled in ChatComposer::handle_key_event_without_popup():

• When steer_enabled is true, Enter calls handle_submission(false) (submit immediately)
• When steer_enabled is false, Enter calls handle_submission(true) (queue)

See codex-rs/tui/src/bottom_pane/chat_composer.rs for the implementation.

Documentation

For more details on the chat composer behavior, see:

• TUI Chat Composer documentation
• Feature flag definition: codex-rs/core/src/features.rs