v0.9.0

• Experimental CollaborationPluginV2__EXPERIMENTAL with externally managed Yjs documents and providers
• Binding V2 synchronization, awareness, cursors, shared undo/redo, and offline/reconnect support
• Experimental Yjs version-diff command support
• Nuxt collaboration playground updated to demonstrate the external V2 lifecycle
• Full test coverage for practical statements, functions, and lines