- Introduced agent-specific cache key isolation to ensure distinct prompt caching across agents.
- Improved reasoning replay handling for Claude models, including cumulative tool turn restoration and validation.
- Enhanced HTTP and WebSocket session consistency during execution scope and cache replay synchronization.
- Added new unit tests and extended coverage for prompt caching, agent isolation, and replay cache functionality.
Closes: #4352
- Updated Antigravity Credits fallback to handle KV store unavailability as a service error.
- Enhanced signature caching mechanisms with request-time KV access and sliding expiration.
- Added and improved tests for KV client interactions, including error handling and expiration behaviors.
- Introduced `CacheSignatureBestEffort` for non-critical signature caching and clarified function flows with required context.
- Ensured consistent error reporting for missing or unavailable KV stores in various scenarios.
- Replaced direct `homekv` calls with injectable KV client interfaces for `antigravity` and `codex_reasoning_replay` modules.
- Improved error reporting and handling for KV operations, including `KVGet`, `KVSet`, `KVDel`, and `KVExpire`.
- Introduced dedicated fake KV clients for expanded and granular test coverage.
- Added new unit tests to validate KV client behaviors and error scenarios, ensuring robustness and sliding expiration functionality.
