[action] Anthropic deprecates temperature, top_p, and top_k parameters on Claude Opus 4.7 and later

Setting temperature, top_p, or top_k to a non-default value returns a 400 error on Claude Opus 4.7 and later, including Claude Opus 4.8 and Claude Sonnet 5. The parameters remain in SDK request types so existing code type-checks. Recommended approach: omit them and guide behavior via prompting. The page does not date this change; announced_at reflects the date it was captured from the page. Severity: action_required. Verification: verified.