Claude Code 2.1.212: /fork becomes a background session, /subtask added, runaway-loop caps

• /fork copies the conversation into a new background session with its own claude agents row; the previous in-session subagent is now /subtask
• Task tool mode parameter deprecated and ignored — subagents inherit the parent session's permission mode
• Session caps: WebSearch calls default 200 (CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION), subagent spawns default 200 (CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION, reset by /clear)
• MCP tool calls over 2 minutes auto-background; tune with CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS
• Added claude auto-mode reset (confirmation prompt, --yes to skip)
• Fixed plan mode auto-running file-modifying Bash commands (touch, rm) with no permission prompt or SDK canUseTool callback
• Fixed worktree creation following a committed symlink at .claude/worktrees, which could write outside the repository
• Fixed a continue:false hook halt being dropped on mid-stream tool failure, and hook infrastructure errors reported as user rejections
• Fixed SIGTERM orphaning a Bash process tree in print/SDK mode; the CLI now kills the tree and exits 143
• Fixed /background and claude --bg failing with uv_spawn errors on Windows when Group Policy blocks PowerShell 5.1
• Several /ultrareview fixes: PR references like #123 and pasted URLs, fetching remote branches, billing confirmation after /clear
• /resume in the agent view opens a picker of past sessions, including deleted ones, and resumes as a background session
• Fixed conversations with many images failing with "Request too large"; web search/fetch retry 529 and rate-limited requests with bounded backoff
• SendMessage bodies no longer duplicated into replayed history and tool results
• Prompt caching's mid-conversation system block now works behind gateways and custom base URLs
• OpenTelemetry: fixed chunked-encoding rejections (411/400) from Azure Monitor, and missing trace_id/span_id when TRACEPARENT is set

Note: the source entry is truncated mid-bullet at the end (Enterprise forceLoginMethod enforcement).