Bun 1.4

Bun 1.4 represents a major update that adds 1,517 new tests from the Node.js test suite, significantly improving compatibility as a Node.js drop-in replacement. The release includes performance improvements (5x lower idle CPU usage, up to 35% less memory, 50% faster startup on Linux), major new features like Bun.Image, Bun.WebView, parallel test running, and a complete rewrite from Zig to Rust. It also fixes over 2,900 issues and enables compatibility with popular tools like Playwright, Next.js 16, and vitest.