v8.9.0-dev.10

• Merge pull request #1729 from kaitranntt/kai/docs/hardening-inventory-refresh-post-1727
• docs: refresh hardening inventory after #1727
• Merge pull request #1727 from KennethWKZ/feat/claude-fable-5-1
• fix(extended-context): manage ANTHROPIC_DEFAULT_MODEL and keep the overlay in sync
• fix(extended-context): suffix the Fable tier and default it on 1M launches
• fix(extended-context): never write [1m] into the Fable tier key
• feat(models): add Claude Fable 5.1 and correct Sonnet 5 pricing