Add WYSIWYG editor

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rich-text editing is becoming increasingly essential, especially with AI-generated content and dynamic components. While WYSIWYG editors are notoriously hard to implement—requiring accessibility, formatting, and real-time collaboration support—Shadcn could provide a well-integrated, lightweight solution that matches its design system. Current third-party options are inconsistent with Shadcn’s UI, require extra styling, and increase dependency bloat. A native Shadcn editor would improve developer experience, ensure seamless integration with Radix UI, and future-proof applications as AI-driven content generation grows.