Fixes

• Welcome notebook has doubled content #8213
• Some ANSI terminal output have have "sticky" bold text #8212 #8215

Warnings for macOS Signed Builds

The advantage of these builds is Apple has vetted them, and you thus avoid the security warning when launching Kui. However, due to underlying Electron/nodejs bugs, they can be quite laggy, though still usable. See the discussion here. Hopefully the underlying bugs will be fixed soon, so we can mainstream the signed builds.