Claude API version 2026-10-21: temperature removed, new SDK majors (TS 1.0, Python 2.0)

Since 2026-10-21 the current Claude API version is `2026-10-21`. `temperature`, `top_p` and `top_k` are removed (400 on every model, even at the default). `@anthropic-ai/sdk` 1.0 and `anthropic` 2.0 send the new version, drop those parameters from their types, send the key as `Authorization: Bearer`, and accept one credential per client.