Under the hood
Startup now measures an added "firstCommandMountJoin" wait before the first command runs
What
During interactive startup, after the existing wait for MCP servers to be ready (mcp_prewait_ms), Claude Code now also waits for and measures a new firstCommandMountJoin step before running the first command.
Why
This adds visibility into another part of startup timing, letting slowdowns before the first command runs be tracked more precisely.