Summary

Removes the redundant preferredProvider variable in ProviderCommandReactor.ts that always equals threadProvider.

Details

threadProvider is defined as currentProvider ?? inferProviderForModel(thread.model). The subsequent preferredProvider was defined as currentProvider ?? threadProvider, which collapses to threadProvider in all cases:

• When currentProvider is defined: threadProvider === currentProvider, so both resolve to currentProvider.
• When currentProvider is undefined: the ?? falls through, so preferredProvider === threadProvider.

The fix removes the preferredProvider declaration and replaces its two usages with threadProvider.