54b4844d3f
Implement resolveModelWithFallback() that tries: 1) user override, 2) fuzzy match from requirements chain against available models, 3) system default. Export new model utilities from shared index. Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-opencode) Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>