feat: Initial commit - Train tracking system

Complete real-time train tracking system for Spanish railways (Renfe/Cercanías):

- Backend API (Node.js/Express) with GTFS-RT polling workers
- Frontend dashboard (React/Vite) with Leaflet maps
- Real-time updates via Socket.io WebSocket
- PostgreSQL/PostGIS database with Flyway migrations
- Redis caching layer
- Docker Compose configuration for development and production
- Gitea CI/CD workflows (lint, auto-tag, release)
- Production deployment with nginx + Let's Encrypt SSL

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

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

frontend/nginx.conf

@@ -0,0 +1,44 @@
+# Configuración de nginx para el contenedor frontend
+server {
+    listen 80;
+    server_name localhost;
+    root /usr/share/nginx/html;
+    index index.html;
+
+    # Logs
+    access_log /var/log/nginx/access.log;
+    error_log /var/log/nginx/error.log;
+
+    # Gzip compression
+    gzip on;
+    gzip_vary on;
+    gzip_min_length 1000;
+    gzip_types text/plain text/css text/xml text/javascript
+               application/json application/javascript application/xml+rss
+               application/x-javascript application/xhtml+xml;
+
+    # SPA fallback - todas las rutas devuelven index.html
+    location / {
+        try_files $uri $uri/ /index.html;
+    }
+
+    # Cache para assets estáticos con hash
+    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff|woff2|ttf|eot)$ {
+        expires 1y;
+        add_header Cache-Control "public, immutable";
+        try_files $uri =404;
+    }
+
+    # No cachear index.html
+    location = /index.html {
+        expires -1;
+        add_header Cache-Control "no-cache, no-store, must-revalidate";
+    }
+
+    # Denegar acceso a archivos ocultos
+    location ~ /\. {
+        deny all;
+        access_log off;
+        log_not_found off;
+    }
+}