## What's changed
- `/fork` now copies your conversation into a new background session (its own row in `claude agents`) while you keep working; the in-session subagent it used to launch is now `/subtask`
- Added `claude auto-mode reset` to restore the default auto-mode configuration, with a confirmation prompt (pass `--yes` to skip)
- Added a session-wide limit on WebSearch tool calls (default 200, tunable via `CLAUDE_CODE_MAX_WEB_SEARCHES_PER_SESSION`) to stop runaway search loops
- Added a per-session cap on subagent spawns (default 200, override with `CLAUDE_CODE_MAX_SUBAGENTS_PER_SESSION`) to stop runaway delegation loops; `/clear` resets the budget
- MCP tool calls running longer than 2 minutes now move to the background automatically so the session stays usable; configure the threshold or disable with `CLAUDE_CODE_MCP_AUTO_BACKGROUND_MS`
- Typing `/resume` in the agent view now opens a picker of past sessions — including sessions deleted from the list — and resumes your pick as a background session
- Fixed plan mode auto-running file-modifying Bash commands (e.g. `touch`, `rm`) without a permission prompt or SDK `canUseTool` callback
- Fixed worktree creation following a repository-committed symlink at `.claude/worktrees`, which could create files outside the repository
- Fixed a `continue:false` hook's halt being dropped when the tool fails or completes mid-stream, and hook infrastructure errors being misreported as user rejections
- Fixed SIGTERM during a running Bash tool orphaning the command's process tree in print/SDK mode; the CLI now aborts the turn, kills the tree, and exits 143
- Fixed `/background` and `claude --bg` failing with "EUNKNOWN: unknown error, uv_spawn" on Windows when Group Policy blocks PowerShell 5.1; the daemon now prefers PowerShell 7
- Fixed shell mode (`!`) not executing commands containing file paths while the path autocomplete popup was open
- Fixed auto-mode denial notifications rendering broken characters when a long denial reason was truncated mid-emoji
- Fixed Ctrl+J not inserting a newline in the agent view dispatch input on terminals with extended key reporting, and surfaced the newline shortcut in the `?` help overlay
- Fixed `/ultrareview` rejecting PR references like `#123`, `PR 123`, and pasted PR URLs; error hints now name the command you actually typed
- Fixed `/ultrareview <branch>` not fetching the branch from origin when it exists remotely; it now suggests the closest branch name on typos
- Fixed `/ultrareview` skipping the billing confirmation in a new conversation after `/clear`
- Fixed `/ultrareview`'s "not a git repository" error on Claude Desktop now suggesting the project's repository folder instead of terminal commands
- Fixed hosted (host-managed) sessions failing at startup when repository settings configured mTLS certs, extra CA bundles, or OAuth scopes; these transport settings are now ignored with a warning
- Fixed a spurious "File has not been read yet" error when editing a file that had been read with offset/limit before resuming a session
- Fixed `ExitWorktree` failing with "no active EnterWorktree session" after resuming a session with `--continue`/`--resume` in print/SDK mode
- Fixed the workflow agent grid staying empty for Remote Control clients that join a session mid-run
- Fixed streaming-mode control requests being marked complete before their handler finished, which could lose the request on session restart
- Fixed background sessions created with `/fork` losing their live-parent protection after a state write failure
- Fixed reopening a stopped background session from the agent view failing silently — it now resumes the session, or shows why it can't and lets you force a restart
- Fixed agent teams: a stopping teammate could send the leader duplicate idle notifications when team initialization re-ran within a session
- Fixed the plan-approval dialog footer splitting "ctrl+g to edit in <editor>" apart when the file path is long
- Fixed the welcome banner keeping its old panel widths after a combined width+height terminal resize in fullscreen mode
- Fixed diff previews losing their line numbers and +/- markers in narrow layouts
- Fixed @-mentions attaching nothing after a partial file read, plugin uninstall targeting the wrong marketplace, and false "Command timed out" on exit code 143
- Fixed OpenTelemetry HTTP exports being rejected with 411/400 by Azure Monitor and other endpoints that don't accept chunked transfer encoding
- Fixed OTLP event log records missing `trace_id`/`span_id` when `TRACEPARENT` is set in SDK/headless mode
- Fixed conversations with many images incorrectly failing with "Request too large" errors, and improved the error message to explain the actual cause
- Fixed web search and web fetch returning "API Error" text as search results or page content when the API was overloaded
- Improved web search and web fetch reliability by retrying 529 errors and rate-limited requests with bounded backoff
- Improved prompt caching: the mid-conversation system block now works behind LLM gateways and custom base URLs (Bedrock, Vertex, 1P)
- Improved background agent attach: cold-attaching now instantly shows the formatted transcript while the session boots, instead of a blank wait
- Reduced token usage in inter-agent messaging: `SendMessage` bodies are no longer duplicated into replayed history and tool results
- Changed `/fork` to name the copy after your prompt when the session has no title, so the row is recognizable in the agent view
- Changed bare `/btw` to reopen the side-question panel on your most recent exchange so you can browse earlier answers
- Changed the `←` footer hint to pulse `N done` for a moment when a background agent finishes while nothing needs your input
- Deprecated the Task tool's `mode` parameter (now ignored); subagents inherit the parent session's permission mode by default
- Changed Enterprise `forceLoginMethod` to be enforced for VS Code extension, SDK, `setup-token`, and `install-github-app` logins, not just the terminal
- Changed session transcripts to record the reasoning effort level on each assistant message
- Changed headless/SDK sessions to apply a `set_model` control request mid-turn; the next model round-trip uses the new model instead of waiting for the next turn
- Changed agent view / `claude agents --json`: sessions waiting on a sandbox, MCP-input, or managed-settings prompt now show as "Needs input" instead of "Working"
- Updated the auth status panel title from "Cloud authentication" to "Authentication"
- Corrected an earlier release note (2.1.200): tmux through the 3.6 series lacks synchronized output; newer tmux with support is detected automatically