[ankit]

Bumps the version to 4.0.4 in package.json and the manifest, and adds the 4.0.4 CHANGELOG section.

• Arc support (fix: make Stylebot usable in Arc #1212) and Vivaldi detection on install (fix: recognise Vivaldi on install and leave its side panel alone #1215)
• Options style editor: stays open after saving, Ctrl+S / ⌘S, Save only enabled with changes (feat(options): save the style editor with Ctrl+S / ⌘S #1207, feat(options): keep the style editor open after saving #1209)
• Popup no longer syncs on open (feat(popup): stop syncing when the popup opens #1213)
• Fix stray "asynchronous response" console errors (fix(background): only keep a message's channel open when it gets an answer #1214)

Review notes: merging triggers release.yml, which tags v4.0.4 and creates the GitHub Release from the changelog.

Testing: CI, including the release-only Edge e2e.

🤖 Generated with Claude Code

[github-actions]

Bundle size

No change to what the popup or content scripts load.

Bundle	Size	Change	Gzip	Change
Popup	178.9 KB	–	48.8 KB	–
fonts/fonts.css	2.9 KB	–	458 B	–
popup/index.css	23.3 KB	–	5.2 KB	–
popup/index.js	152.7 KB	–	43.2 KB	–
Content script (document_start)	90.0 KB	–	23.2 KB	–
editor/index.js	50.8 KB	–	11.9 KB	–
inject-css/index.js	36.1 KB	–	9.8 KB	–
site-bridge/index.js	3.1 KB	–	1.4 KB	–