docs: Claude Code v2.1.217 - Managed Agents model effort + new webhook events + Claude Security plugin

[claude-yolo]

Night shift report

WHY THIS MATTERS: The Python SDK (0.118.0) and TypeScript SDK (0.113.0) both shipped new Managed Agents API surface today — model effort levels (low/medium/high/xhigh/max) let callers control reasoning cost vs. quality, threads delta streaming is live, and a batch of new webhook event types covers Environment and MemoryStore lifecycle. Separately, the Claude Code security docs added a new "Claude Security plugin" tier (multi-agent deep scan) to the documented defense-in-depth stack, and the /branch session docs got a clearer table explaining what in-flight background subagents inherit when you fork.

HIGHLIGHTS:

• Managed Agents model effort — both SDKs now export BetaManagedAgentsEffortLow/Medium/High/Xhigh/Max types; callers can tune per-agent reasoning spend
• Threads delta streaming — client.beta.sessions.threads.events.stream() now accepts params (previously parameterless), enabling finer-grained streaming control
• New webhook event types — Environment (created/updated/archived/deleted) and MemoryStore (created/archived/deleted) lifecycle events in both SDKs; important for teams building event-driven pipelines on top of Managed Agents
• Claude Security plugin — documented in security-guidance.md as a new "on demand, deep scan" layer: multi-agent vulnerability scan with independently reviewed findings and patches; links to /docs/en/claude-security
• /branch behavior clarified — sessions.md now explicitly documents that in-flight background subagents and Bash commands keep running and their output appears in the new branch, not the original; "allow for this session" grants do NOT carry over
• Claude Code v2.1.217 in manifest

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