Two silent Claude Code behavior changes worth auditing.

Hook matchers are now exact-match instead of substring, so a matcher like code-reviewer silently stopped firing. Switch to regex like mcp__brave-search__.* to match a hyphenated MCP server's tools (Changelog). And the streaming idle watchdog now defaults on: no stream events for 5 minutes triggers an abort-and-retry, killing the classic "hung on a silent stream" failure in long headless runs. Disable with CLAUDE_ENABLE_STREAM_WATCHDOG=0 only if you have a legitimately long silent tool call. Both are the kind of quiet change that breaks a pipeline without an error message.