Add persistent user preference recall across Codex CLI conversations

@adrian.a.adewunmi the “ambient defaults vs triggered workflows” line is the whole thing, I think. Skills (and the umbrella-project trick) both need something to fire them — a recognizable task, an invocation. But review depth, PR tone, verbosity, language aren’t workflows you trigger; they’re the baseline the agent should already be standing on before it does anything. The moment you have to remember to invoke your own defaults, they’ve stopped being defaults.

That’s also why the umbrella project rubs wrong — you nailed it. It centralizes context, but it does it by collapsing the two things that actually want to stay apart: “how this codebase works” (local, per-repo) and “how I work” (portable, per-me). Stuffing both into one umbrella just moves the leak around.

The layering you keep coming back to — repo instructions → user defaults → per-chat overrides — is the right shape, and the part I’d stress is that it’s a precedence model, not a merge. User defaults travel with you; repo context stays pinned to its repo and never bleeds into the next one; a per-chat override wins for that chat only and doesn’t quietly graduate into a new default. When I built my own version of this, getting that precedence + the no-leak boundary right was 90% of the value — the storage part was the easy bit.

Whether Codex grows a first-class layer or not, that boundary is the part worth holding out for.