Add persistent user preference recall across Codex CLI conversations

I think skills are a useful part of the answer, especially for repeatable workflows. I use them more like reusable capability modules than personal defaults, though.

For me, the gap is still a first-class layering model. Skills work well when there is a recognisable trigger or workflow, but preferences like review depth, PR tone, commit style, language, verbosity, and default assumptions are more like ambient defaults. I would rather not encode every preference as a skill and then rely on Codex deciding when to invoke it.

An umbrella project also feels like a workaround. It can centralise context, but it blurs the boundary between project-local knowledge and user-level behaviour. I would prefer something closer to:

1. User defaults: portable personal preferences.

2. Repo instructions: project-specific context and commands.

3. Skills: reusable workflows or domain capabilities.

4. Chat overrides: temporary direction for the current task.

Skills are great when I want to say, “use this workflow.” User defaults are better for “this is how I generally like to work.” Both are useful, but they solve different problems.