Remove blocking TCP connectivity tests for fast startup

Eliminates test_tcp_connectivity function that was causing 5-10 second
startup delays. ZMQ connections are non-blocking and we rely entirely
on heartbeat mechanism for connectivity detection. This restores fast
dashboard startup time.

agent/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-agent"
-version = "0.1.71"
+version = "0.1.72"
 edition = "2021"
 
 [dependencies]

dashboard/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard"
-version = "0.1.71"
+version = "0.1.72"
 edition = "2021"
 
 [dependencies]

dashboard/src/communication/mod.rs

@@ -71,12 +71,6 @@ impl ZmqConsumer {
     pub async fn connect_to_host(&mut self, hostname: &str, port: u16) -> Result<()> {
         let address = format!("tcp://{}:{}", hostname, port);
 
-        // First test basic TCP connectivity to the port
-        if let Err(e) = self.test_tcp_connectivity(hostname, port).await {
-            error!("TCP connectivity test failed for {}: {}", address, e);
-            return Err(e);
-        }
-
         match self.subscriber.connect(&address) {
             Ok(()) => {
                 info!("Connected to agent at {}", address);
@@ -90,25 +84,6 @@ impl ZmqConsumer {
         }
     }
 
-    /// Test TCP connectivity to a host and port with timeout
-    async fn test_tcp_connectivity(&self, hostname: &str, port: u16) -> Result<()> {
-        let timeout = std::time::Duration::from_secs(3);
-        
-        match tokio::time::timeout(timeout, tokio::net::TcpStream::connect((hostname, port))).await {
-            Ok(Ok(_stream)) => {
-                debug!("TCP connectivity test passed for {}:{}", hostname, port);
-                Ok(())
-            }
-            Ok(Err(e)) => {
-                debug!("TCP connectivity test failed for {}:{}: {}", hostname, port, e);
-                Err(anyhow::anyhow!("TCP connection failed: {}", e))
-            }
-            Err(_) => {
-                debug!("TCP connectivity test timed out for {}:{}", hostname, port);
-                Err(anyhow::anyhow!("TCP connection timed out"))
-            }
-        }
-    }
 
     /// Connect to predefined hosts using their configuration
     pub async fn connect_to_predefined_hosts(&mut self, hosts: &std::collections::HashMap<String, crate::config::HostDetails>) -> Result<()> {

shared/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "cm-dashboard-shared"
-version = "0.1.71"
+version = "0.1.72"
 edition = "2021"
 
 [dependencies]