@vitest/spy

mocker: Harden manual and redirect mocks [backport to v4]

Revive global concurrency limit for test lifecycle [backport to v4]

browser: Encode iframeId in tester iframe URL [backport to v4]

browser: Trigger playwright/chromium gc on lower disk availability [backport to v4]

mocker: Restrict redirect mocks to the fs allowlist [backport to v4]

browser: Check fs access in builtin commands [backport to v4]

vm: Fix external module resolve error with deps optimizer query for encoded URI [backport to v4]

Fix importOriginal with optimizer and query import [backport to v4] - by Hiroshi Ogawa, David Harris, Codexand Vladimir in #10546

browser: Wait for orchestrator readiness before resolving browser sessions [backport to v4] - by Vladimir and Séamus O'Connor in #10555

browser: Wait for iframe tester readiness before preparing [backport to v4] - by Vladimir and Séamus O'Connor in #10497 and #10556

mocker: Hoist vi.mock() for vite-plus/test imports [backport to v4] - by Hiroshi Ogawa, LongYinan, Claude Opus 4.8 and Vladimir in #10548

pool: Prevent test run hang on worker crash [backport to v4] - by Ari Perkkiö and Jattioui Ismail in #10543 and #10564

browser: Disable client cdp API when allowWrite/allowExec: false [backport to v4]

browser: Remove orphaned Playwright route when same module is mocked via multiple ids [backport to v4]

runner: Limit concurrency per task branch in addition to per leaf callbacks (backport)

Stringify diff objects only once

browser: Provide project reference in ToMatchScreenshotResolvePath

Global sequence.concurrent: true with top-level test(..., { concurrent: false }) + depreacte sequential test API and options

browser: Simplify orchestrator otel carrier

coverage: Istanbul to support instrumenter option

--project negation excludes browser instances

Project color label on html reporter

Fix vi.defineHelper called as object method