feat: CardSidebar layout component and ExperienceCard sidebar redesign

Sidebar: period badge, company, stack tags.
Main: role title and rich-text description.

src/shared/ui/Card/ui/Card.test.tsx

@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react';
-import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardTitle } from './Card';
+import { Card, CardContent, CardDescription, CardFooter, CardHeader, CardSidebar, CardTitle } from './Card';
 
 describe('Card', () => {
   describe('rendering', () => {
@@ -72,3 +72,51 @@ describe('CardFooter', () => {
     expect(el).toHaveClass('brutal-border-top', 'mt-6', 'pt-6', 'md:mt-8', 'md:pt-8');
   });
 });
+describe('CardSidebar', () => {
+  describe('rendering', () => {
+    it('renders sidebar content', () => {
+      render(<CardSidebar sidebar={<span>Sidebar</span>}>Main</CardSidebar>);
+      expect(screen.getByText('Sidebar')).toBeInTheDocument();
+    });
+
+    it('renders main content', () => {
+      render(<CardSidebar sidebar={<span>Sidebar</span>}>Main</CardSidebar>);
+      expect(screen.getByText('Main')).toBeInTheDocument();
+    });
+  });
+
+  describe('structure', () => {
+    it('root wrapper is a flex container', () => {
+      const { container } = render(<CardSidebar sidebar={<span>S</span>}>M</CardSidebar>);
+      expect(container.firstChild).toHaveClass('flex');
+    });
+
+    it('sidebar column has brutal-border-sidebar class', () => {
+      render(<CardSidebar sidebar={<span>Sidebar</span>}>Main</CardSidebar>);
+      const sidebar = screen.getByText('Sidebar').parentElement;
+      expect(sidebar).toHaveClass('brutal-border-sidebar');
+    });
+
+    it('sidebar column has fixed width on md', () => {
+      render(<CardSidebar sidebar={<span>Sidebar</span>}>Main</CardSidebar>);
+      const sidebar = screen.getByText('Sidebar').parentElement;
+      expect(sidebar).toHaveClass('md:w-52');
+    });
+
+    it('main column fills remaining space', () => {
+      render(<CardSidebar sidebar={<span>Sidebar</span>}>Main</CardSidebar>);
+      expect(screen.getByText('Main')).toHaveClass('flex-1');
+    });
+  });
+
+  describe('className passthrough', () => {
+    it('forwards className to the root wrapper', () => {
+      const { container } = render(
+        <CardSidebar sidebar={<span>S</span>} className="custom">
+          M
+        </CardSidebar>,
+      );
+      expect(container.firstChild).toHaveClass('custom');
+    });
+  });
+});