🎨 Feature: Configuration Tailwind + Templates PHP + Page Canary

Stories 1.2, 1.3, 1.4:
- Tailwind CSS configuré avec palette sombre personnalisée
- Templates header.php et footer.php avec meta SEO/Open Graph
- Fonction include_template() pour les composants réutilisables
- Page canary avec animations et composants de test
- Configuration nginx exemple pour le déploiement
- Dépendances: vlucas/phpdotenv, tailwindcss, postcss, autoprefixer

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tailwind.config.js

@@ -0,0 +1,55 @@
+/** @type {import('tailwindcss').Config} */
+module.exports = {
+  content: [
+    './*.php',
+    './pages/**/*.php',
+    './templates/**/*.php',
+    './assets/js/**/*.js'
+  ],
+  theme: {
+    extend: {
+      colors: {
+        primary: {
+          DEFAULT: '#FA784F',
+          light: '#FB9570',
+          dark: '#E5623A',
+        },
+        background: '#17171F',
+        surface: {
+          DEFAULT: '#1E1E28',
+          light: '#2A2A36',
+        },
+        border: '#3A3A48',
+        text: {
+          primary: '#F5F5F7',
+          secondary: '#A1A1AA',
+          muted: '#71717A',
+        },
+        success: '#34D399',
+        warning: '#FBBF24',
+        error: '#F87171',
+        info: '#60A5FA',
+      },
+      fontFamily: {
+        sans: ['Inter', 'system-ui', 'sans-serif'],
+        mono: ['JetBrains Mono', 'monospace'],
+      },
+      fontSize: {
+        'display': ['2.5rem', { lineHeight: '1.2', fontWeight: '700' }],
+        'heading': ['2rem', { lineHeight: '1.3', fontWeight: '600' }],
+        'subheading': ['1.5rem', { lineHeight: '1.4', fontWeight: '600' }],
+        'body': ['1rem', { lineHeight: '1.6', fontWeight: '400' }],
+        'small': ['0.875rem', { lineHeight: '1.5', fontWeight: '400' }],
+      },
+      maxWidth: {
+        'content': '1280px',
+      },
+      boxShadow: {
+        'card': '0 4px 20px rgba(0, 0, 0, 0.25)',
+        'card-hover': '0 10px 40px rgba(0, 0, 0, 0.3)',
+        'input-focus': '0 0 0 3px rgba(250, 120, 79, 0.2)',
+      },
+    },
+  },
+  plugins: [],
+}