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>

lib/api/queries.ts

@@ -0,0 +1,206 @@
+'use client';
+
+import { useQuery, useMutation, UseQueryOptions } from '@tanstack/react-query';
+import { pastelAPI } from './client';
+import type {
+  ColorInfoRequest,
+  ColorInfoData,
+  ConvertFormatRequest,
+  ConvertFormatData,
+  ColorManipulationRequest,
+  ColorManipulationData,
+  ColorMixRequest,
+  ColorMixData,
+  RandomColorsRequest,
+  RandomColorsData,
+  DistinctColorsRequest,
+  DistinctColorsData,
+  GradientRequest,
+  GradientData,
+  NamedColorsData,
+  HealthData,
+} from './types';
+
+// Color Information
+export const useColorInfo = (
+  request: ColorInfoRequest,
+  options?: Omit<UseQueryOptions<ColorInfoData>, 'queryKey' | 'queryFn'>
+) => {
+  return useQuery({
+    queryKey: ['colorInfo', request.colors],
+    queryFn: async () => {
+      const response = await pastelAPI.getColorInfo(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+    enabled: request.colors.length > 0 && request.colors.every((c) => c.length > 0),
+    ...options,
+  });
+};
+
+// Format Conversion
+export const useConvertFormat = () => {
+  return useMutation({
+    mutationFn: async (request: ConvertFormatRequest) => {
+      const response = await pastelAPI.convertFormat(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+// Color Manipulation
+export const useLighten = () => {
+  return useMutation({
+    mutationFn: async (request: ColorManipulationRequest) => {
+      const response = await pastelAPI.lighten(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useDarken = () => {
+  return useMutation({
+    mutationFn: async (request: ColorManipulationRequest) => {
+      const response = await pastelAPI.darken(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useSaturate = () => {
+  return useMutation({
+    mutationFn: async (request: ColorManipulationRequest) => {
+      const response = await pastelAPI.saturate(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useDesaturate = () => {
+  return useMutation({
+    mutationFn: async (request: ColorManipulationRequest) => {
+      const response = await pastelAPI.desaturate(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useRotate = () => {
+  return useMutation({
+    mutationFn: async (request: ColorManipulationRequest) => {
+      const response = await pastelAPI.rotate(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useComplement = () => {
+  return useMutation({
+    mutationFn: async (colors: string[]) => {
+      const response = await pastelAPI.complement(colors);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useMixColors = () => {
+  return useMutation({
+    mutationFn: async (request: ColorMixRequest) => {
+      const response = await pastelAPI.mix(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+// Color Generation
+export const useGenerateRandom = () => {
+  return useMutation({
+    mutationFn: async (request: RandomColorsRequest) => {
+      const response = await pastelAPI.generateRandom(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useGenerateDistinct = () => {
+  return useMutation({
+    mutationFn: async (request: DistinctColorsRequest) => {
+      const response = await pastelAPI.generateDistinct(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+export const useGenerateGradient = () => {
+  return useMutation({
+    mutationFn: async (request: GradientRequest) => {
+      const response = await pastelAPI.generateGradient(request);
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+  });
+};
+
+// Named Colors
+export const useNamedColors = () => {
+  return useQuery({
+    queryKey: ['namedColors'],
+    queryFn: async () => {
+      const response = await pastelAPI.getNamedColors();
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+    staleTime: Infinity, // Named colors never change
+  });
+};
+
+// Health Check
+export const useHealth = () => {
+  return useQuery({
+    queryKey: ['health'],
+    queryFn: async () => {
+      const response = await pastelAPI.getHealth();
+      if (!response.success) {
+        throw new Error(response.error.message);
+      }
+      return response.data;
+    },
+    refetchInterval: 60000, // Check every minute
+  });
+};