fix(react): improve prop serialization

[mpesic]

Pull request checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Build (npm run build) was run locally for affected output targets
• Tests (npm test) were run locally and passed
• Prettier (npm run prettier) was run locally and passed

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe):

What is the current behavior?

• In SSR boolean props set to false (someProp={false}) are serialized to some-prop="false". This is incorrect per the spec: https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#boolean-attributes and causes FOUC issues.

• In SSR Stencil components with shadow: { delegatesFocus: true } are not properly serialized with shadowrootdelegatesfocus, causing interaction issues.

Issue URL:

What is the new behavior?

• Removes false boolean attributes
• Adds shadowrootdelegatesfocus where necessary.

Does this introduce a breaking change?

• Yes
• No

Other information