feat(fxt): wire broker check subcommand into CLI

Add Broker variant to Commands enum with BrokerArgs (flatten),
route to execute_broker_command in match block (no JWT required),
exit(1) on check failure. Clone config.api_gateway_url to avoid
partial move. Add two CLI parsing tests for broker check.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

bin/fxt/src/main.rs

@@ -21,6 +21,7 @@ use fxt::{
         agent::{execute_agent_command, AgentArgs},
         auth::{execute_auth_command, AuthCommand},
         backtest_ml::{execute_backtest_ml_command, BacktestMlArgs},
+        broker::{execute_broker_command, BrokerArgs},
         model::{execute_model_command, ModelCommand},
         trade::{execute_trade_command, TradeArgs},
         train::{execute_train_command, TrainCommand},
@@ -212,6 +213,21 @@ enum Commands {
         trade_args: TradeArgs,
     },
 
+    /// Broker connectivity check
+    #[clap(
+        long_about = "Validate broker connectivity.\n\n\
+        Checks:\n\
+        1. Direct IB Gateway: TCP + ibapi handshake\n\
+        2. Broker Gateway gRPC: HealthCheck + SessionStatus\n\n\
+        Examples:\n\
+          fxt broker check\n\
+          fxt broker check --host 10.0.0.5 --port 4002\n\
+          fxt broker check --skip-ibkr"
+    )]
+    Broker {
+        #[command(flatten)]
+        broker_args: BrokerArgs,
+    },
 }
 
 /// JWT token claims structure for validation
@@ -381,7 +397,7 @@ async fn main() -> Result<()> {
     // Merge: CLI args override config file (precedence: CLI > Config > Default)
     if cli.api_gateway_url == "http://localhost:50051" {
         // Using default, check if config has override
-        cli.api_gateway_url = config.api_gateway_url;
+        cli.api_gateway_url = config.api_gateway_url.clone();
     }
 
     if cli.log_level == "info" {
@@ -432,6 +448,13 @@ async fn main() -> Result<()> {
             let jwt_token = load_jwt_token(&cli.api_gateway_url).await?;
             execute_trade_command(trade_args, &cli.api_gateway_url, &jwt_token).await
         }
+        Commands::Broker { broker_args } => {
+            let passed = execute_broker_command(broker_args, &config).await?;
+            if !passed {
+                std::process::exit(1);
+            }
+            Ok(())
+        }
     }
 }
 #[cfg(test)]
@@ -537,4 +560,31 @@ mod tests {
             _ => panic!("Expected Auth command"),
         }
     }
+
+    #[test]
+    fn test_cli_parsing_broker_check() {
+        let cli = Cli::parse_from(&["fxt", "broker", "check"]);
+        match cli.command {
+            Commands::Broker { .. } => {},
+            _ => panic!("Expected Broker command"),
+        }
+    }
+
+    #[test]
+    fn test_cli_parsing_broker_check_with_flags() {
+        let cli = Cli::parse_from(&[
+            "fxt",
+            "broker",
+            "check",
+            "--host",
+            "10.0.0.5",
+            "--port",
+            "4001",
+            "--skip-gateway",
+        ]);
+        match cli.command {
+            Commands::Broker { .. } => {},
+            _ => panic!("Expected Broker command"),
+        }
+    }
 }