Fix Bedrock effort and regional routing (#61597)

Fixes Amazon Bedrock adaptive-thinking requests so the selected effort
reaches Anthropic models, and routes Claude Opus 4.7 and 4.8 through
their documented Japanese and Canadian inference profiles.

Release Notes:

- Fixed Amazon Bedrock effort selection and regional routing for Claude
Opus 4.7 and 4.8.
9dcc3c2909Richard Feldman committed on 7/27/2026, 3:59:19 PM· committed by GitHubparentc29ba6c
2 files changedLine totals unavailable