feat: añadir configuración Docker con usuario appuser y seguridad reforzada

- Dockerfile multi-stage con usuario no-root (UID 1001)
- docker-compose.yml con seguridad reforzada (read-only, capabilities limitadas)
- nginx.conf optimizado con headers de seguridad y puerto 8080
- package.json para build de Tailwind CSS
- .dockerignore para optimizar contexto de construcción

nginx.conf

@@ -0,0 +1,65 @@
+user appuser;
+worker_processes auto;
+error_log /var/log/nginx/error.log warn;
+pid /var/run/nginx.pid;
+
+events {
+    worker_connections 1024;
+}
+
+http {
+    include /etc/nginx/mime.types;
+    default_type application/octet-stream;
+    
+    log_format main '$remote_addr - $remote_user [$time_local] "$request" '
+                    '$status $body_bytes_sent "$http_referer" '
+                    '"$http_user_agent" "$http_x_forwarded_for"';
+    
+    access_log /var/log/nginx/access.log main;
+    
+    sendfile on;
+    tcp_nopush on;
+    tcp_nodelay on;
+    keepalive_timeout 65;
+    types_hash_max_size 2048;
+    
+    # Configuración de seguridad
+    server_tokens off;
+    add_header X-Frame-Options "SAMEORIGIN" always;
+    add_header X-Content-Type-Options "nosniff" always;
+    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+    add_header X-XSS-Protection "1; mode=block" always;
+    
+    server {
+        listen 8080;
+        server_name localhost;
+        root /usr/share/nginx/html;
+        index index.html;
+        
+        # Configuración de seguridad adicional
+        add_header X-Frame-Options "SAMEORIGIN" always;
+        add_header X-Content-Type-Options "nosniff" always;
+        add_header Referrer-Policy "strict-origin-when-cross-origin" always;
+        add_header X-XSS-Protection "1; mode=block" always;
+        
+        # Manejo de archivos estáticos
+        location ~* \.(css|js|ico|png|jpg|jpeg|gif|svg|woff|woff2|ttf|eot)$ {
+            expires 1y;
+            add_header Cache-Control "public, immutable";
+            add_header X-Frame-Options "SAMEORIGIN" always;
+            add_header X-Content-Type-Options "nosniff" always;
+        }
+        
+        # Manejo de HTML
+        location / {
+            try_files $uri $uri/ /index.html;
+            add_header X-Frame-Options "SAMEORIGIN" always;
+            add_header X-Content-Type-Options "nosniff" always;
+        }
+        
+        # Negar acceso a archivos ocultos
+        location ~ /\. {
+            deny all;
+        }
+    }
+}