- Add GroupConfig with 7 variants (default, card, section, inset, flex-row, flex-col, centered)
- Add TextInputConfig with 2 variants (default, error) and 4 states
- Add ImageConfig with 3 variants (default, rounded, circle)
- Register all 5 configs in initElementConfigs()
- Node creation hook already implemented in NodeGraphNode constructor
- Total: 5 configs with 28 variants across all elements
- All configs use design tokens for theming
MVP 2 Status: ✅ Complete (ready for integration testing)