docs(readme): document refs, onNodeMount, and element-specific usage 🍋

- Add Form UX (label for, inputmode, enterkeyhint) and SVG/accessibility examples
- Add Image, Responsive images (picture/srcset/sizes), iframe, and Links (anchor) sections
- Add Refs and lifecycle section with refs, onNodeMount, and AbortController examples
- Document RenderOptions and validation errors in API and type reference
- Update Quick Start and API table for render(schema, container, options?)

Author: NeaByteLab

README.md

@@ -48,7 +48,7 @@ npm install @neabyte/schema2ui
 
 ## Quick Start
 
-Define a tree with `root` (array of nodes). Each node has `type` (HTML tag name), optional `layout`, `style`, `attrs`, `content`, and `children`. Call `create(definition)` then `render(schema, container)`.
+Define a tree with `root` (array of nodes). Each node has `type` (HTML tag name), optional `layout`, `style`, `attrs`, `content`, and `children`. Call `create(definition)` then `render(schema, container)`. For refs and lifecycle (events, dialog, focus), use `render(schema, container, { refs, onNodeMount })` — see [USAGE](USAGE.md#refs-and-lifecycle).
 
 ```typescript
 import { create, render } from '@neabyte/schema2ui'
@@ -120,7 +120,7 @@ render(schema, document.getElementById('app'))
 
 ## Documentation
 
-- **[USAGE.md](USAGE.md)** — Full API and type reference.
+- **[USAGE.md](USAGE.md)** — API and type reference.
 - **[examples/](examples/)** — Browser demo: build then open `examples/index.html`.
 
 ## Build & Test