[breaking] Amazon Bedrock retires Jamba 1.5 Large, Jamba 1.5 Mini (EOL 2026-11-26)

Amazon Bedrock moves AI21 Labs Jamba 1.5 Large, AI21 Labs Jamba 1.5 Mini to Legacy on 2026-05-26 with end-of-life on 2026-11-26 (public extended access from 2026-08-26, at provider-set pricing). Bedrock lifecycle dates are platform-specific and may differ from the model provider's own schedule. announced_at reflects the documented Legacy date, when Bedrock notifies users. Effective: 2026-11-26. Affected: amazon/ai21.jamba-1-5-large-v1:0, amazon/ai21.jamba-1-5-mini-v1:0. Severity: breaking. Verification: verified.