Claude Code 2.1.300 adds prompt.change hooks, agent transcript views, and OTel GenAI attrs
Claude Code 2.1.300 adds a prompt.change mod hook for non-typed prompt edits (history recall, clear, undo, plugin fill), $.ui.view({ agentId }) to show an agent transcript in the main view, and OpenTelemetry GenAI semantic attributes on trace spans. It also splits cache-write metrics into 5-minute and 1-hour buckets and lets agent.spawn rewrite workflow-agent prompt and model fields.
