Port: declare 'model:' in opencode-rescue agent frontmatter #39

Port of openai/codex-plugin-cc#169 (merged)

Current state

plugins/opencode/agents/opencode-rescue.md has no model field in its frontmatter:

---
name: opencode-rescue
description: Proactively use when Claude Code is stuck, wants a second implementation or diagnosis pass, needs a deeper root-cause investigation, or should hand a substantial coding task to OpenCode through the shared runtime
tools: Bash
skills:
  - opencode-runtime
  - opencode-prompting
---

Without model, Claude Code assigns whatever default tier it chooses at runtime, giving no tier guarantee and an unpredictable cost profile.

Why it matters

opencode-rescue is a thin forwarding wrapper — its entire job is to invoke opencode-companion.mjs task ... via a single Bash call, apply trivial routing logic (--background vs --wait, --resume vs --fresh), and return the companion stdout unchanged. It does not need a heavy reasoning tier.

Fix

Add a model: field. Upstream picked sonnet (not haiku) because the routing logic — detecting "continue"/"fresh" intent, choosing background vs foreground based on task complexity — is slightly above pure mechanical forwarding. Match upstream:

 ---
 name: opencode-rescue
 description: Proactively use when Claude Code is stuck, wants a second implementation or diagnosis pass, needs a deeper root-cause investigation, or should hand a substantial coding task to OpenCode through the shared runtime
+model: sonnet
 tools: Bash
 skills:
   - opencode-runtime
   - opencode-prompting
 ---

If subsequent testing shows haiku handles the routing reliably, downgrade. The important thing is that the field is declared explicitly so users have a cost guarantee.

Upstream reference

openai/codex-plugin-cc#169 (merged 2026-04-08).