design: two-color palette — rename all tokens to --cream / --blue

Replace ochre-clay, carbon-black, burnt-oxide, slate-indigo with clean
two-color system: --cream (#f4f0e8) and --blue (#041cf3). Update every
component, utility class, and test assertion.

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

@@ -13,17 +13,13 @@ describe('Card', () => {
     });
   });
   describe('background variants', () => {
-    it('defaults to ochre background', () => {
+    it('defaults to cream background', () => {
       const { container } = render(<Card>Content</Card>);
-      expect(container.firstChild).toHaveClass('bg-ochre-clay');
+      expect(container.firstChild).toHaveClass('bg-cream');
     });
-    it('applies slate background', () => {
-      const { container } = render(<Card background="slate">Content</Card>);
-      expect(container.firstChild).toHaveClass('bg-slate-indigo');
-    });
-    it('applies white background', () => {
-      const { container } = render(<Card background="white">Content</Card>);
-      expect(container.firstChild).toHaveClass('bg-white');
+    it('applies blue background', () => {
+      const { container } = render(<Card background="blue">Content</Card>);
+      expect(container.firstChild).toHaveClass('bg-blue');
     });
   });
   describe('padding', () => {

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

@@ -1,7 +1,7 @@
 import type { ReactNode } from 'react';
 import { cn } from '$shared/lib';
 
-export type CardBackground = 'ochre' | 'slate' | 'white';
+export type CardBackground = 'cream' | 'blue';
 
 interface CardProps {
   /**
@@ -14,7 +14,7 @@ interface CardProps {
   className?: string;
   /**
    * Background color preset
-   * @default 'ochre'
+   * @default 'cream'
    */
   background?: CardBackground;
   /**
@@ -25,15 +25,14 @@ interface CardProps {
 }
 
 const BG: Record<CardBackground, string> = {
-  ochre: 'bg-ochre-clay',
-  slate: 'bg-slate-indigo text-ochre-clay',
-  white: 'bg-white',
+  cream: 'bg-cream',
+  blue: 'bg-blue text-cream',
 };
 
 /**
  * Brutalist card container with background and padding variants.
  */
-export function Card({ children, className, background = 'ochre', noPadding = false }: CardProps) {
+export function Card({ children, className, background = 'cream', noPadding = false }: CardProps) {
   return (
     <div className={cn('brutal-border brutal-shadow', BG[background], !noPadding && 'p-6 md:p-8', className)}>
       {children}