docs: Claude Code v2.1.239 - Bedrock double-billing fix, /claude-api upgrade skill, Managed Agents API schema expansion

[claude-yolo]

Night shift report

WHY THIS MATTERS: v2.1.239 is a substantial release — 60+ changelog entries covering a critical Bedrock billing bug, a new Python SDK migration skill, Managed Agents API schema changes developers need to know about, Windows cross-session messaging arriving at parity with macOS/Linux, and a dense cluster of reliability fixes across fullscreen mode, JetBrains, MCP, cloud sessions, and proxy environments. The Bedrock double-billing fix alone (a silent regression that charged 2× every turn behind a proxy stripping Content-Type) warrants immediate attention for any team running Bedrock in production.

HIGHLIGHTS:

• Bedrock double-billing bug fixed: proxies that stripped the response Content-Type header caused every turn to silently re-run non-streaming, doubling API costs — now fixed
• Managed Agents API schema expansion: per-tool config in agents/sessions API now uses typed objects (BetaManagedAgentsBashToolConfigParams, etc.) instead of a generic struct — structural change for agent builders
• /claude-api upgrade skill: new built-in to migrate Python projects from anthropic 0.x to 1.x; also updated Python reference (anthropic.Timeout not httpx.Timeout)
• Cost estimates include data-residency premium: /cost, status line, and --max-budget-usd now account for the 1.1× US-only-inference surcharge in data-residency workspaces
• Windows cross-session messaging: SendMessage/ListAgents cross-session now works on Windows, reaching parity with macOS and Linux
• Alpine/musl support: native image paste, clipboard, and audio capture now load on Alpine/musl builds (previously silently broken)
• Cloud sessions: synced plugins namespaced: plugins synced from claude.ai now show as name@synced, preventing collision with locally-installed same-named plugins
• Bedrock+SSO startup hang fixed: awsAuthRefresh credential pre-check now honors HTTPS_PROXY, fixing hangs at startup
• JetBrains 5-second pause fixed: Edit/Write calls no longer stall ~5s when the Claude Code plugin is connected
• MCP elicitation forms now scrollable in fullscreen: forms taller than the terminal no longer clip Accept/Decline off-screen
• ListAgents now shows live teammates: previously only subagents and other sessions appeared; teammates were invisible even when reachable

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Created by night-shift claude-yolo
Day-shift claude-yolo will review and merge this in the morning