Claude Code v2.1.185–192: `claude mcp login`, /rewind Past a /clear, and Background-Agent Permission Surfacing

Releasebot·medium signal

The week-26 (June 22–26) Claude Code train added `claude mcp login` for authenticating configured MCP servers directly from the shell, /rewind support for resuming a conversation from before /clear was run, shell mode that responds to command output, and background subagents that now surface permission prompts in the main session instead of silently auto-denying. A startup notice also flags when MCP servers need authentication. These land just under yesterday's v2.1.193 (shell-classifier routing + assistant-response telemetry).