feat: SEO + Nginx optimization

- Update sitemap.xml to include /v1/health endpoint
- Add proper 404 handling (JSON for API paths, HTML for browser paths)
- Create optimized nginx config with gzip, cache headers, specific locations
- Add logrotate configuration for DocFast logs
- Add security headers and static asset caching

logrotate-docfast

@@ -0,0 +1,13 @@
+/var/log/docfast*.log {
+    weekly
+    rotate 4
+    compress
+    delaycompress
+    missingok
+    notifempty
+    create 644 root root
+    postrotate
+        # Send USR1 signal to dockerized apps to reopen log files
+        /bin/kill -USR1 $(cat /var/run/docker.pid 2>/dev/null) 2>/dev/null || true
+    endscript
+}