Claude Code v2.1.203 Fixes Many Background Agent Stability Issues and Reduces Memory Usage

Claude Code v2.1.203 is a major maintenance release fixing dozens of bugs and introducing several improvements. Key fixes include: resolving a 15-20 second stall on macOS when switching background agents due to false low-memory detection; fixing background sessions that permanently failed after daemon token expiration (now auto-recover); preventing silent sub-agent interruptions and restarts when returning to Claude Agents (now inherits previous work); and fixing memory and per-round CPU regressions in interactive sessions (context usage indicator no longer re-analyzes full conversation each round). Additionally, it fixes Windows background agents inheriting incorrect PATH causing missing tools, cross-worktree sub-agents executing commands in wrong directories, and cyclic background agent crashes (now reports error once when workdir is deleted). Performance-wise, lazy-loading large dependencies reduces binary size by ~7 MB and startup memory by ~7 MB. Live preview updates during long response streams no longer re-render the entire screen, improving response speed. Sub-agent behavior is improved, with less tendency to delegate entire tasks to another sub-agent. Also, left arrow no longer closes background tasks, diff, and workflow detail views (Esc key is used instead). New features include login-expiry warnings, gray pause badge for manual permission mode, and extra workdirs added to MCP roots/list. The VSCode version adds an "Enable Remote Control for all sessions" toggle. Developers using Claude Code for long-running background automation will benefit from reduced risk of agent interruption due to environment or token issues; teams working in large multi-repo workspaces will find cross-worktree fixes provide more reliable isolation. After upgrading, note the left-arrow behavior change and use /doctor and /status to check startup warnings.