- Component testing shifts to a story/gallery model with a new fixtures.mount() API for scoped locators and type‑checked props.
- Adds abort‑signal cancellation, WebP screenshot support, isolated retry strategy, and multiple new APIs (credentials storage, scroll option, apiResponse.timing, locator.waitForFunction, function arguments for evaluate/initScript).
- Introduces Reporter.preprocess hook, HTML report mergeFiles option, bundles the Playwright MCP server/CLI, and drops Debian 11 support (breaking change).