Fix data caching to prevent empty broadcasts

CRITICAL FIX: Collectors now update cached AgentData instead of
creating new empty data each cycle. This prevents the dashboard
from seeing flashing/disappearing data.

- Add cached_agent_data field to Agent struct
- Update cached data when collectors run
- Always broadcast the full cached data every 2s
- Only individual collectors respect their intervals
- Bump version to v0.1.230

agent/src/agent.rs

@@ -34,6 +34,7 @@ pub struct Agent {
     collectors: Vec<TimedCollector>,
     notification_manager: NotificationManager,
     previous_status: Option<SystemStatus>,
+    cached_agent_data: AgentData,
 }
 
 /// Track system component status for change detection
@@ -143,6 +144,9 @@ impl Agent {
         let notification_manager = NotificationManager::new(&config.notifications, &hostname)?;
         info!("Notification manager initialized");
 
+        // Initialize cached agent data
+        let cached_agent_data = AgentData::new(hostname.clone(), env!("CARGO_PKG_VERSION").to_string());
+
         Ok(Self {
             hostname,
             config,
@@ -150,6 +154,7 @@ impl Agent {
             collectors,
             notification_manager,
             previous_status: None,
+            cached_agent_data,
         })
     }
 
@@ -199,10 +204,8 @@ impl Agent {
     async fn collect_and_broadcast(&mut self) -> Result<()> {
         debug!("Starting structured data collection");
 
-        // Initialize empty AgentData
-        let mut agent_data = AgentData::new(self.hostname.clone(), env!("CARGO_PKG_VERSION").to_string());
-
         // Collect data from collectors whose intervals have elapsed
+        // Update cached_agent_data with new data
         let now = Instant::now();
         for timed_collector in &mut self.collectors {
             let should_collect = match timed_collector.last_collection {
@@ -211,7 +214,7 @@ impl Agent {
             };
 
             if should_collect {
-                if let Err(e) = timed_collector.collector.collect_structured(&mut agent_data).await {
+                if let Err(e) = timed_collector.collector.collect_structured(&mut self.cached_agent_data).await {
                     error!("Collector {} failed: {}", timed_collector.name, e);
                     // Update last_collection time even on failure to prevent immediate retries
                     timed_collector.last_collection = Some(now);
@@ -226,13 +229,22 @@ impl Agent {
             }
         }
 
+        // Update timestamp on cached data
+        self.cached_agent_data.timestamp = std::time::SystemTime::now()
+            .duration_since(std::time::UNIX_EPOCH)
+            .unwrap()
+            .as_secs();
+
+        // Clone for notification check (to avoid borrow issues)
+        let agent_data_snapshot = self.cached_agent_data.clone();
+
         // Check for status changes and send notifications
-        if let Err(e) = self.check_status_changes_and_notify(&agent_data).await {
+        if let Err(e) = self.check_status_changes_and_notify(&agent_data_snapshot).await {
             error!("Failed to check status changes: {}", e);
         }
 
-        // Broadcast the structured data via ZMQ
-        if let Err(e) = self.zmq_handler.publish_agent_data(&agent_data).await {
+        // Broadcast the cached structured data via ZMQ
+        if let Err(e) = self.zmq_handler.publish_agent_data(&agent_data_snapshot).await {
             error!("Failed to broadcast agent data: {}", e);
         } else {
             debug!("Successfully broadcast structured agent data");