[BUG] codex:codex-rescue hangs in worktrees when run_in_background is used

Summary

codex:codex-rescue tasks hang indefinitely when dispatched with isolation: "worktree" and the rescue agent uses run_in_background: true on the Bash call. The worktree is cleaned up before Codex finishes, leaving Codex running in a deleted directory.

Root Cause

1. Rescue agent calls codex-companion.mjs task --write with run_in_background: true
2. Bash returns immediately ("Command running in background...")
3. Rescue agent returns "Codex task dispatched in background" and exits
4. CC sees agent returned with no file changes → deletes the worktree
5. Codex is now running in a deleted directory → hangs at "Turn started"

The rescue agent uses run_in_background in two cases:

• Explicitly: --background flag in the task text is interpreted as run_in_background: true
• Implicitly: For large prompts with long timeouts, Claude sometimes independently decides to background the call

Repro

# SUCCEEDS — rescue agent waits for Codex to complete:
Agent(subagent_type="codex:codex-rescue", isolation="worktree",
      prompt="Create foo.txt with content hello")

# FAILS — rescue agent backgrounds, worktree cleaned before Codex finishes:
Agent(subagent_type="codex:codex-rescue", isolation="worktree",
      prompt="Create foo.txt with content hello. --background")

Parallel dispatch without --background works fine — three concurrent worktree tasks all succeed. The issue is purely about early worktree cleanup from backgrounding.

Suggested Fix

In codex-cli-runtime SKILL.md, change the --background handling from:

- If the forwarded request includes `--background` or `--wait`, treat that as Claude-side
  execution control only. Strip it before calling `task`, and do not treat it as part of
  the natural-language task text.

To:

- If the forwarded request includes `--background` or `--wait`, strip it before calling
  `task`. Do NOT set `run_in_background` on the Bash call. The rescue agent MUST wait for
  Codex to complete — backgrounding causes the parent worktree to be cleaned up before
  Codex finishes, silently orphaning the task.

Impact

Any codex:codex-rescue dispatched with isolation: "worktree" where the rescue agent backgrounds the Bash call will silently fail. No error, no timeout — just an indefinite hang at "Turn started" with Codex working in a deleted directory.

Environment

• Claude Code 2.1.89
• codex-plugin-cc (marketplace install)
• macOS Darwin 25.2.0

Start with codex-cli-runtime SKILL.md and inspect the rescue agent's handling of --background and --wait before the codex-companion.mjs task --write call. Verify the worktree reproduction with isolation set to worktree, then confirm the rescue agent waits for Codex and that the task completes without leaving Codex in a deleted directory.