Claude Code 2.1.212 adds /fork, /subtask, session limits

/fork now copies conversation to a new background session while you keep working, and /subtask replaces the in-session subagent. New session-wide limits cap WebSearch at 200 calls and subagent spawns at 200 per session to prevent runaway loops. Fixes include Windows spawn error when Group Policy blocks PowerShell 5.1 and plan mode auto-running file-modifying Bash commands.