feat: ViewTransitionWrapper shared component with stable react-dom fallback

Wraps children in React's ViewTransition (canary API) when available,
falling back to Fragment in environments where ViewTransition is undefined
(test env, stable react-dom). Add react/canary to tsconfig types to
expose the ViewTransition component type.

src/shared/ui/ViewTransitionWrapper/index.ts

@@ -0,0 +1 @@
+export { ViewTransitionWrapper } from './ui/ViewTransitionWrapper';

src/shared/ui/ViewTransitionWrapper/ui/ViewTransitionWrapper.test.tsx

@@ -0,0 +1,33 @@
+import { render, screen } from '@testing-library/react';
+import { ViewTransitionWrapper } from './ViewTransitionWrapper';
+
+describe('ViewTransitionWrapper', () => {
+  it('renders children', () => {
+    render(
+      <ViewTransitionWrapper name="test">
+        <p>Hello</p>
+      </ViewTransitionWrapper>,
+    );
+    expect(screen.getByText('Hello')).toBeInTheDocument();
+  });
+
+  it('renders multiple children', () => {
+    render(
+      <ViewTransitionWrapper name="test">
+        <p>First</p>
+        <p>Second</p>
+      </ViewTransitionWrapper>,
+    );
+    expect(screen.getByText('First')).toBeInTheDocument();
+    expect(screen.getByText('Second')).toBeInTheDocument();
+  });
+
+  it('does not add an extra wrapper DOM element', () => {
+    const { container } = render(
+      <ViewTransitionWrapper name="test">
+        <p>Content</p>
+      </ViewTransitionWrapper>,
+    );
+    expect(container.firstChild?.nodeName).toBe('P');
+  });
+});

src/shared/ui/ViewTransitionWrapper/ui/ViewTransitionWrapper.tsx

@@ -0,0 +1,26 @@
+import { Fragment, type ReactNode, ViewTransition as VT } from 'react';
+
+/**
+ * VT is undefined in stable react-dom (test env / non-experimental builds).
+ * Fall back to Fragment so children render and the name prop is silently ignored.
+ */
+const Transition = (VT ?? Fragment) as typeof VT;
+
+type Props = {
+  /**
+   * Maps to the view-transition-name CSS property
+   */
+  name: string;
+  /**
+   * Content to animate
+   */
+  children: ReactNode;
+};
+
+/**
+ * Wraps children in React's ViewTransition when available,
+ * falling back to a Fragment in environments where ViewTransition is undefined.
+ */
+export function ViewTransitionWrapper({ name, children }: Props) {
+  return <Transition name={name}>{children}</Transition>;
+}

src/shared/ui/index.ts

@@ -10,3 +10,4 @@ export { RichText } from './RichText';
 export type { ContainerSize, SectionBackground } from './Section';
 export { Container, Section } from './Section';
 export { TechStackBrick, TechStackGrid } from './TechStack';
+export { ViewTransitionWrapper } from './ViewTransitionWrapper';

tsconfig.json

@@ -18,7 +18,7 @@
         "name": "next"
       }
     ],
-    "types": ["vitest/globals"],
+    "types": ["vitest/globals", "react/canary"],
     "paths": {
       "@/*": ["./*"],
       "$shared/*": ["./src/shared/*"],