Claude Code v2.1.310 adds Monitor tool and plugin monitors, blocks long foreground sleeps

Anthropic shipped Claude Code v2.1.310 on October 23, adding the Monitor tool and plugin monitors on Bedrock, Vertex, and Foundry, including when telemetry and nonessential traffic are disabled. Long foreground sleeps are now blocked, and the release fixes gateway compatibility with rejected effort-2025-11-24 beta values, mid-conversation system messages, background cleanup deleting recent files, compaction after 'Prompt is too long', and symlink visibility in file-read prompts.