feat: initial Next.js 15 implementation with TypeScript and Tailwind CSS 4

Add complete project structure and foundation:

**Core Setup:**
- Next.js 15.5.6 with App Router and React 19
- TypeScript 5.7 with strict mode
- Tailwind CSS 4.1 with custom theme configuration
- ESLint and Prettier configuration

**Dependencies Installed:**
- @tanstack/react-query - Server state management
- zustand - Client state management
- framer-motion - Animations
- lucide-react - Icon library
- react-colorful - Color picker component
- cmdk - Command palette
- sonner - Toast notifications
- clsx + tailwind-merge - Class name utilities

**Project Structure:**
- app/ - Next.js App Router pages
- components/ - React components (ui, color, tools, layout, providers)
- lib/ - Utilities, API client, hooks, stores, constants
- tests/ - Unit and E2E test directories

**API Integration:**
- Type-safe Pastel API client with all 21 endpoints
- Complete TypeScript type definitions for requests/responses
- Error handling and response types

**UI Components:**
- Button component with variants (default, outline, ghost, destructive)
- Input component with focus states
- Providers wrapper (React Query, Toast)
- Root layout with Inter font and metadata

**Pages:**
- Home page with gradient hero and feature cards
- Links to playground and palette generation (pages pending)

**Configuration:**
- Tailwind with HSL color variables for theming
- Dark/light mode CSS variables
- Custom animations (fade-in, slide-up, slide-down)
- @tailwindcss/forms and @tailwindcss/typography plugins

Build successful: 102 kB First Load JS, static generation working.

Ready for color components and playground implementation.

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

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

package.json

@@ -0,0 +1,59 @@
+{
+  "name": "pastel-ui",
+  "version": "0.1.0",
+  "private": true,
+  "description": "Modern web UI for color manipulation, palette generation, and accessibility analysis",
+  "author": "valknarness",
+  "license": "MIT",
+  "packageManager": "pnpm@10.20.0",
+  "scripts": {
+    "dev": "next dev",
+    "dev:turbo": "next dev --turbopack",
+    "build": "next build",
+    "start": "next start",
+    "lint": "next lint",
+    "lint:fix": "next lint --fix",
+    "format": "prettier --write \"**/*.{js,jsx,ts,tsx,json,css,md}\"",
+    "type-check": "tsc --noEmit",
+    "test": "vitest",
+    "test:ui": "vitest --ui",
+    "test:e2e": "playwright test",
+    "test:e2e:ui": "playwright test --ui",
+    "analyze": "ANALYZE=true next build"
+  },
+  "dependencies": {
+    "@tanstack/react-query": "^5.62.11",
+    "clsx": "^2.1.1",
+    "cmdk": "^1.0.4",
+    "framer-motion": "^11.15.0",
+    "lucide-react": "^0.468.0",
+    "next": "^15.1.3",
+    "react": "^19.0.0",
+    "react-colorful": "^5.6.1",
+    "react-dom": "^19.0.0",
+    "sonner": "^1.7.1",
+    "tailwind-merge": "^2.5.5",
+    "zustand": "^5.0.2"
+  },
+  "devDependencies": {
+    "@playwright/test": "^1.49.1",
+    "@tailwindcss/forms": "^0.5.9",
+    "@tailwindcss/typography": "^0.5.15",
+    "@testing-library/react": "^16.1.0",
+    "@testing-library/user-event": "^14.5.2",
+    "@types/node": "^22.10.2",
+    "@types/react": "^19.0.1",
+    "@types/react-dom": "^19.0.2",
+    "@typescript-eslint/eslint-plugin": "^8.46.3",
+    "@typescript-eslint/parser": "^8.46.3",
+    "@vitest/ui": "^2.1.8",
+    "eslint": "^9.17.0",
+    "eslint-config-next": "^15.1.3",
+    "postcss": "^8.4.49",
+    "prettier": "^3.4.2",
+    "tailwindcss": "^4.0.0",
+    "typescript": "^5.7.2",
+    "vitest": "^2.1.8",
+    "webpack-bundle-analyzer": "^4.10.2"
+  }
+}