bridge: explore permission mirroring (interaction/* callbacks) to replace --mode yolo

Context

The desktop never lets the core approve risky actions on its own: the core must ask via interaction/requestPermission and the host mirrors the request to the UI as an elicitation event, then answers with respond(id, decision).

Our fork runs --mode yolo - no gate between the model and the machine. Codex already has approval plumbing on its side of the bridge, so the missing piece is a core surface that can ask.

Proposal

• exploratory: drive a core surface with callbacks so each permission request becomes a Codex-side approval request
• --mode yolo becomes the explicit fallback, not the default
• likely depends on the warm-process experiment (#23), since the stream-json surface has no callback channel

Evidence

zcode-article/ui-core-interaction.md, "The host middleware around raw RPC" and "Ideas to borrow" item 2.

Start with zcode-article/ui-core-interaction.md, especially “The host middleware around raw RPC” and “Ideas to borrow” item 2. Compare the proposed callback surface with the warm-process experiment in issue #23 and determine whether permission requests can reach Codex-side approval; done means the feasibility, dependencies, and fallback behavior are documented.