feat(wix-app): integrate a11y review into Editor React Component flow

[InnerDesires]

Summary

• Add an automated a11y scan + triage workflow to the wix-app skill's Editor React Component creation flow.
• New reference editor-react-component/A11Y-REVIEW.md defines the workflow as a step inside the existing Editor React Component process, using Wix CLI verification commands (npx wix build && npx wix generate manifest, npx tsc --noEmit) and cross-linking the existing ACCESSIBILITY.md for ARIA conventions.
• New editor-react-component/a11y-review/ subfolder ships the supporting docs (RULES.md, FIX-STRATEGIES.md, MANUAL-REVIEW-CHECKLIST.md, CONFIDENCE-MODEL.md, EXAMPLES.md, SEMANTIC-RESOLUTION.md) and two scanner scripts under skills/wix-app/scripts/ (scan-a11y-eslint.js, scan-a11y-code.js).
• EDITOR_REACT_COMPONENT.md workflow now invokes the A11y Review after editing .tsx/.module.css and before regenerating the manifest; topic references list updated to surface the new doc next to ACCESSIBILITY.md.

Test plan

• Scaffold an Editor React Component in a Wix CLI app and follow the updated workflow end-to-end.
• Run both scanners on the component's .tsx files from the project root and confirm JSON output parses cleanly.
• Introduce a deliberate a11y violation (e.g. icon-only <button> with no label) and confirm it is flagged, triaged, and fixable per the guide.
• Confirm npx wix build && npx wix generate manifest and npx tsc --noEmit still pass after fixes.
• Spot-check internal links in A11Y-REVIEW.md and the updated EDITOR_REACT_COMPONENT.md.