Release 0.4.0

[olehwebdev]

What and why

Release 0.4.0: everything merged since 0.3.0. That covers the Network panel and response overrides, breakpoints, rules, source-map originals, actions, the website and Actions panel in windows of their own, the page stack, and the component inspector with Renders and Stores. The branch ends with its version commit, as CONTRIBUTING › Releasing describes.

• README is organised around when to use the app:
  • a "Use it when…" table first;
  • then a section per use case, each with a screenshot: fix a live site, test UI states against API data, find the component behind an element, see why it rendered and what the store did, debug iframes and micro-frontends, block requests and change headers.
  • The flow diagram gives way to a short paragraph. Install, updates, data and limitations stay. The roadmap lists what's next and points to the CHANGELOG for what shipped.
• Media, recorded again in the current design:
  • docs/demo.gif: the checkout fix;
  • docs/inspect.gif (new): pick an element of a production React shop, see its component traced to the source, and why each click rendered what;
  • screenshots editor, network, renders, stores and console replace editor, diff, palette and iframes.
• CHANGELOG: the 0.4.0 notes, which the app shows as What's New:
  • open with what the release is about;
  • group the additions by theme: the inspector, data flow, the network, the rest;
  • read as one release rather than as the steps it was built in.
• Version commit: package.json and the lockfile move to 0.4.0; the CHANGELOG section is dated 2026-09-26, with its compare links.

How it was tested

• node scripts/release-notes.ts 0.4.0 prints the section followed by the download table, as the Release workflow does.
• The CHANGELOG unit test passes: every release is dated, and package.json's version is covered.
• Every README image link resolves to a file in the tree.
• The screenshots and GIFs were captured from the built app, driven by Playwright under Xvfb against the demo site (/store/, /services.html) and a production React + Redux Toolkit shop with a source map.
• Local results on this exact tree: npm run typecheck and every lint pass; npm test 1,171 passed; xvfb-run -a npm run test:e2e 109 passed.

Checklist

• Comes from a git flow branch (feature/…, bugfix/…) into main, and does one thing: a release/ branch, ending with its version commit
• npm run typecheck, npm run lint:fsd, npm run lint:structure, npm run lint, npm run lint:unused, npm run lint:duplicates, npm run lint:secrets, npm test and npm run test:e2e pass
• docs/SPEC.md describes any behaviour this changes (no behaviour changes here)
• User-visible changes are noted under [Unreleased] in CHANGELOG.md (now [0.4.0])

Releasing (for the maintainer)

Once CI passes:

1. Run the Release workflow on release/0.4.0 with Draft release ticked.
2. Merge this PR with a merge commit.
3. Check that git ls-remote --tags origin v0.4.0 prints nothing, then publish the draft.