In-session `/profile` command for Codex CLI

Motivation

Codex CLI can select a profile at startup, but switching profiles in the middle of an active session currently requires restarting.

Requested feature

It would be useful to have an in-session /profile command that lets me switch between named profiles already defined in ~/.codex/config.toml.

Example profiles

[profiles.lite]
model = "gpt-5.4-mini"
model_reasoning_effort = "low"

[profiles.lite-fast]
model = "gpt-5.4-mini"
model_reasoning_effort = "low"
service_tier = "fast"

[profiles.deep-fast]
model = "gpt-5.5"
model_reasoning_effort = "high"
service_tier = "fast"

[profiles.deep-fast-xhigh]
model = "gpt-5.5"
model_reasoning_effort = "xhigh"
service_tier = "fast"

Example commands

/profile lite
/profile lite-fast
/profile deep-fast
/profile deep-fast-xhigh

Expected behavior

When a profile is switched during a session:

• Codex loads the selected profile from config
• the new profile applies to subsequent turns
• the current conversation context stays intact
• the UI shows the active profile
• Codex clearly indicates if any settings require a restart

Use case

A lighter lite or lite-fast profile would be helpful for quick questions, while deep-fast or deep-fast-xhigh would be useful for harder reasoning or implementation work, without needing to start a new session.

Notes

This is specifically about switching profiles mid-session, not only at startup.