fix(omo): sync recommended models with upstream and improve Fill Recommended feedback

The Fill Recommended button was misleading — it showed toast.success even
when most slots couldn't be filled due to model ID mismatches with the
user's configured providers.

Changes:
- Sync OMO_BUILTIN_AGENTS/CATEGORIES recommended fields with upstream
  oh-my-openagent model-requirements (gpt-5.4→5.5, kimi-k2.5→claude-sonnet-4-6, etc.)
- Add toast.warning tier when unmatched >= filled, showing slot:model pairs
  (e.g. "Sisyphus: claude-opus-4-7") so users know exactly what to configure
- Upgrade fillRecommendedNoMatch to also show examples
- Add fillRecommendedMostlyUnmatched i18n key (zh/en/ja/zh-TW)