🚀 Feature: Router PHP + Pages projets (Stories 3.2 & 3.3)

Story 3.2 - Router PHP et URLs propres:
- Router PHP léger (43 lignes) avec support {slug}
- Front controller index.php
- .htaccess pour Apache
- Pages: home, projects, project-single, skills, about, contact, 404

Story 3.3 - Page liste projets vedettes:
- Grille responsive (1→2→3 colonnes)
- Template project-card.php réutilisable
- Badges technologies (max 4 + compteur)
- Lazy loading images avec fallback SVG

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

includes/router.php

@@ -0,0 +1,45 @@
+<?php
+/**
+ * Router simple pour URLs propres
+ * < 50 lignes de code
+ */
+
+class Router
+{
+    private array $routes = [];
+
+    public function add(string $pattern, string $handler): self
+    {
+        // Convertit {param} en regex ([^/]+)
+        $regex = preg_replace('/\{(\w+)\}/', '([^/]+)', $pattern);
+        $regex = '#^' . $regex . '$#';
+        $this->routes[$regex] = $handler;
+        return $this;
+    }
+
+    public function resolve(string $uri): array
+    {
+        $uri = parse_url($uri, PHP_URL_PATH);
+        $uri = rtrim($uri, '/') ?: '/';
+
+        foreach ($this->routes as $regex => $handler) {
+            if (preg_match($regex, $uri, $matches)) {
+                array_shift($matches); // Enlève le match complet
+                return [$handler, $matches];
+            }
+        }
+
+        return ['pages/404.php', []];
+    }
+
+    public function dispatch(): void
+    {
+        $uri = $_SERVER['REQUEST_URI'] ?? '/';
+        [$handler, $params] = $this->resolve($uri);
+
+        // Rend les paramètres accessibles
+        $GLOBALS['routeParams'] = $params;
+
+        require __DIR__ . '/../' . $handler;
+    }
+}