feat: implement color playground with interactive picker and info display

Add complete color manipulation interface:

**Color Components:**
- ColorPicker - Interactive hex color picker with text input
  - Uses react-colorful for visual selection
  - Manual input support for any color format
  - Real-time updates

- ColorDisplay - Large color preview swatch
  - Configurable sizes (sm, md, lg, xl)
  - Optional border styling
  - Accessible with ARIA labels

- ColorInfo - Comprehensive color information display
  - Shows all formats: Hex, RGB, HSL, Lab, OkLab
  - Copy to clipboard functionality for each format
  - Displays brightness, luminance, light/dark type
  - Shows named color matches

**API Integration:**
- React Query hooks for all Pastel API endpoints
  - useColorInfo - Get color information
  - useConvertFormat - Format conversion
  - useLighten, useDarken, useSaturate, etc. - Manipulations
  - useGenerateRandom, useGenerateDistinct, useGenerateGradient
  - useNamedColors - Cached named colors list
  - Automatic error handling and loading states

**Playground Page (/playground):**
- Two-column layout: picker + info
- Live color preview with large swatch
- Real-time API integration with loading states
- Error handling with user-friendly messages
- Quick action buttons (ready for implementation)
- Responsive grid layout

**Features:**
- Toast notifications for clipboard copy
- Loading spinners during API calls
- Error display with helpful messages
- Accessible keyboard navigation
- Smooth transitions and animations

Build successful with playground page rendering! Ready for color manipulation actions.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/color/ColorDisplay.tsx

@@ -0,0 +1,38 @@
+'use client';
+
+import { cn } from '@/lib/utils/cn';
+
+interface ColorDisplayProps {
+  color: string;
+  size?: 'sm' | 'md' | 'lg' | 'xl';
+  className?: string;
+  showBorder?: boolean;
+}
+
+export function ColorDisplay({
+  color,
+  size = 'lg',
+  className,
+  showBorder = true,
+}: ColorDisplayProps) {
+  const sizeClasses = {
+    sm: 'h-16 w-16',
+    md: 'h-32 w-32',
+    lg: 'h-48 w-48',
+    xl: 'h-64 w-64',
+  };
+
+  return (
+    <div
+      className={cn(
+        'rounded-lg transition-all',
+        showBorder && 'ring-2 ring-border',
+        sizeClasses[size],
+        className
+      )}
+      style={{ backgroundColor: color }}
+      role="img"
+      aria-label={`Color swatch: ${color}`}
+    />
+  );
+}

components/color/ColorInfo.tsx

@@ -0,0 +1,92 @@
+'use client';
+
+import { ColorInfo as ColorInfoType } from '@/lib/api/types';
+import { Button } from '@/components/ui/button';
+import { Copy } from 'lucide-react';
+import { toast } from 'sonner';
+import { cn } from '@/lib/utils/cn';
+
+interface ColorInfoProps {
+  info: ColorInfoType;
+  className?: string;
+}
+
+export function ColorInfo({ info, className }: ColorInfoProps) {
+  const copyToClipboard = (value: string, label: string) => {
+    navigator.clipboard.writeText(value);
+    toast.success(`Copied ${label} to clipboard`);
+  };
+
+  const formatRgb = (rgb: { r: number; g: number; b: number; a?: number }) => {
+    if (rgb.a !== undefined && rgb.a < 1) {
+      return `rgba(${rgb.r}, ${rgb.g}, ${rgb.b}, ${rgb.a})`;
+    }
+    return `rgb(${rgb.r}, ${rgb.g}, ${rgb.b})`;
+  };
+
+  const formatHsl = (hsl: { h: number; s: number; l: number; a?: number }) => {
+    if (hsl.a !== undefined && hsl.a < 1) {
+      return `hsla(${Math.round(hsl.h)}°, ${Math.round(hsl.s * 100)}%, ${Math.round(hsl.l * 100)}%, ${hsl.a})`;
+    }
+    return `hsl(${Math.round(hsl.h)}°, ${Math.round(hsl.s * 100)}%, ${Math.round(hsl.l * 100)}%)`;
+  };
+
+  const formatLab = (lab: { l: number; a: number; b: number }) => {
+    return `lab(${lab.l.toFixed(1)}, ${lab.a.toFixed(1)}, ${lab.b.toFixed(1)})`;
+  };
+
+  const formats = [
+    { label: 'Hex', value: info.hex },
+    { label: 'RGB', value: formatRgb(info.rgb) },
+    { label: 'HSL', value: formatHsl(info.hsl) },
+    { label: 'Lab', value: formatLab(info.lab) },
+    { label: 'OkLab', value: formatLab(info.oklab) },
+  ];
+
+  return (
+    <div className={cn('space-y-4', className)}>
+      <div className="grid grid-cols-1 gap-3">
+        {formats.map((format) => (
+          <div
+            key={format.label}
+            className="flex items-center justify-between p-3 bg-muted rounded-lg"
+          >
+            <div className="flex-1">
+              <div className="text-xs text-muted-foreground mb-1">{format.label}</div>
+              <div className="font-mono text-sm">{format.value}</div>
+            </div>
+            <Button
+              size="icon"
+              variant="ghost"
+              onClick={() => copyToClipboard(format.value, format.label)}
+              aria-label={`Copy ${format.label} value`}
+            >
+              <Copy className="h-4 w-4" />
+            </Button>
+          </div>
+        ))}
+      </div>
+
+      <div className="grid grid-cols-2 gap-3 pt-2 border-t">
+        <div className="space-y-1">
+          <div className="text-xs text-muted-foreground">Brightness</div>
+          <div className="text-sm font-medium">{(info.brightness * 100).toFixed(1)}%</div>
+        </div>
+        <div className="space-y-1">
+          <div className="text-xs text-muted-foreground">Luminance</div>
+          <div className="text-sm font-medium">{(info.luminance * 100).toFixed(1)}%</div>
+        </div>
+        <div className="space-y-1">
+          <div className="text-xs text-muted-foreground">Type</div>
+          <div className="text-sm font-medium">{info.is_light ? 'Light' : 'Dark'}</div>
+        </div>
+        {info.name && (
+          <div className="space-y-1">
+            <div className="text-xs text-muted-foreground">Named</div>
+            <div className="text-sm font-medium">{info.name}</div>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

components/color/ColorPicker.tsx

@@ -0,0 +1,38 @@
+'use client';
+
+import { HexColorPicker } from 'react-colorful';
+import { Input } from '@/components/ui/input';
+import { cn } from '@/lib/utils/cn';
+
+interface ColorPickerProps {
+  color: string;
+  onChange: (color: string) => void;
+  className?: string;
+}
+
+export function ColorPicker({ color, onChange, className }: ColorPickerProps) {
+  const handleInputChange = (e: React.ChangeEvent<HTMLInputElement>) => {
+    const value = e.target.value;
+    // Allow partial input while typing
+    onChange(value);
+  };
+
+  return (
+    <div className={cn('space-y-4', className)}>
+      <HexColorPicker color={color} onChange={onChange} className="w-full" />
+      <div className="space-y-2">
+        <label htmlFor="color-input" className="text-sm font-medium">
+          Color Value
+        </label>
+        <Input
+          id="color-input"
+          type="text"
+          value={color}
+          onChange={handleInputChange}
+          placeholder="#ff0099 or rgb(255, 0, 153)"
+          className="font-mono"
+        />
+      </div>
+    </div>
+  );
+}