Mastra `@mastra/core@1.27.0` adds browser automation and Tavily tools

The April 23, 2026 Mastra release (`@mastra/core@1.27.0`) ships several notable additions. A new `@mastra/browser-viewer` package enables CLI-driven browser automation via Playwright with remote debugging, automatic CDP URL injection for browser CLIs (`agent-browser`, `browser-use`, `browse`), thread-isolated sessions, and live screencast streaming to Studio. A new `@mastra/tavily` package wraps `@tavily/core` as first-class Mastra tools, exposing `createTavilySearchTool`, `createTavilyExtractTool`, `createTavilyCrawlTool`, and `createTavilyMapTool` with full Zod schemas. The release also fixes a critical bug where parallel `foreach` iterations lost their `suspendPayload` during sibling resumes, and corrects observational memory message duplication by force-disabling `savePerStep` when observational memory is active.