Implement dual host configuration: bind_host and hostname

- Replace 'host' config with separate 'bind_host' and 'hostname'
- bind_host: IP/interface for server binding (default 0.0.0.0)
- hostname: Domain for URI validation (required)
- Update all parsing and validation code
- Create dist/ directory with systemd service, config, and install guide
- Add comprehensive INSTALL.md with setup instructions

src/server.rs

@@ -40,7 +40,7 @@ pub async fn serve_file(
 pub async fn handle_connection(
     mut stream: TlsStream<TcpStream>,
     dir: &str,
-    expected_host: &str,
+    hostname: &str,
     expected_port: u16,
     max_concurrent_requests: usize,
     _test_processing_delay: u64,
@@ -97,7 +97,7 @@ pub async fn handle_connection(
             }
 
             // Parse Gemini URL
-            let path = match parse_gemini_url(&request, expected_host, expected_port) {
+            let path = match parse_gemini_url(&request, hostname, expected_port) {
                 Ok(p) => p,
                 Err(_) => {
                     logger.log_error(59, "Invalid URL format");