Install Caddy with rate limiting plugin for ARM64 deployment

- Install Go 1.21.5 for ARM64 architecture
- Use xcaddy to build Caddy with caddy-ratelimit plugin
- Create custom systemd service for plugin-enabled Caddy
- Restore rate limiting configuration in Caddyfile
- Production-ready setup with proper security and rate limiting
- Automatic SSL with enhanced protection against API abuse

scripts/Caddyfile

@@ -41,7 +41,7 @@ yourdomain.com {
     # Gzip compression
     encode gzip zstd
     
-    # Logging for security monitoring
+    # Logging for monitoring
     log {
         output file /var/log/caddy/icewatch.log {
             roll_size 100MB
@@ -50,7 +50,7 @@ yourdomain.com {
         format json
     }
     
-    # Rate limiting for API endpoints
+    # Rate limiting for API endpoints (requires caddy-ratelimit plugin)
     rate_limit {
         zone api {
             key {remote_host}