chore(cli) deprecate --full-auto (#20133)

## Summary
Starts the process of getting rid of `--full-auto`, with some
concessions:
1. Fully removes the command from the tui, since it just resolves to the
default permissions there, and encourages users to use the one-time
trust flow if they're not in a trusted repo.
2. Marks the command as deprecated in `codex exec`, in case users are
actively relying on this. We'll remove in an upcoming n+X release.
3. Cleans up some of the `codex sandbox` cli logic, to keep supporting
legacy sandbox policies for now.

This isn't the cleanest setup, but I think it is worthwhile to warn
users for one release before hard-removing it.

## Testing 
- [x] Updated unit tests

codex-cli/scripts/run_in_container.sh

@@ -92,4 +92,4 @@ quoted_args=""
 for arg in "$@"; do
   quoted_args+=" $(printf '%q' "$arg")"
 done
-docker exec -it "$CONTAINER_NAME" bash -c "cd \"/app$WORK_DIR\" && codex --full-auto ${quoted_args}"
+docker exec -it "$CONTAINER_NAME" bash -c "cd \"/app$WORK_DIR\" && codex --sandbox workspace-write --ask-for-approval on-request ${quoted_args}"