[breaking] Amazon Bedrock retires Nova Premier, Nova Sonic (EOL 2026-09-14)

Amazon Bedrock moves Amazon Nova Premier, Amazon Nova Sonic to Legacy on 2026-03-13 with end-of-life on 2026-09-14. 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: 2026-09-14. Affected: amazon/amazon.nova-premier-v1:0, amazon/amazon.nova-sonic-v1:0. Severity: breaking. Verification: verified.