The required Provider.Request settings field and tsgo's literal
narrowing broke typecheck in llm and core; CI missed it because turbo
replayed cached typecheck results for packages whose own sources did
not change.
- anthropic-messages: lower adaptive thinking display with explicit
literal branches so tsgo keeps the union type
- runner model: annotate providerOptions with its index-signature
return type
- tests: construct provider requests with the now-required settings
field and copy them mutably for plugin drafts
