Implement hysteresis for metric status changes to prevent flapping

Add comprehensive hysteresis support to prevent status oscillation near
threshold boundaries while maintaining responsive alerting.

Key Features:
- HysteresisThresholds with configurable upper/lower limits
- StatusTracker for per-metric status history
- Default gaps: CPU load 10%, memory 5%, disk temp 5°C

Updated Components:
- CPU load collector (5-minute average with hysteresis)
- Memory usage collector (percentage-based thresholds)
- Disk temperature collector (SMART data monitoring)
- All collectors updated to support StatusTracker interface

Cache Interval Adjustments:
- Service status: 60s → 10s (faster response)
- Disk usage: 300s → 60s (more frequent checks)
- Backup status: 900s → 60s (quicker updates)
- SMART data: moved to 600s tier (10 minutes)

Architecture:
- Individual metric status calculation in collectors
- Centralized StatusTracker in MetricCollectionManager
- Status aggregation preserved in dashboard widgets

dashboard/src/main.rs

@@ -1,14 +1,14 @@
 use anyhow::Result;
 use clap::Parser;
-use tracing::{info, error};
+use tracing::{error, info};
 use tracing_subscriber::EnvFilter;
 
 mod app;
-mod config;
 mod communication;
+mod config;
+mod hosts;
 mod metrics;
 mod ui;
-mod hosts;
 mod utils;
 
 use app::Dashboard;
@@ -21,11 +21,11 @@ struct Cli {
     /// Increase logging verbosity (-v, -vv)
     #[arg(short, long, action = clap::ArgAction::Count)]
     verbose: u8,
-    
+
     /// Configuration file path
     #[arg(short, long)]
     config: Option<String>,
-    
+
     /// Run in headless mode (no TUI, just logging)
     #[arg(long)]
     headless: bool,
@@ -34,16 +34,16 @@ struct Cli {
 #[tokio::main]
 async fn main() -> Result<()> {
     let cli = Cli::parse();
-    
+
     // Setup logging - only if headless or verbose
     if cli.headless || cli.verbose > 0 {
         let log_level = match cli.verbose {
-            0 => "warn",  // Only warnings and errors when not verbose
+            0 => "warn", // Only warnings and errors when not verbose
             1 => "info",
-            2 => "debug", 
+            2 => "debug",
             _ => "trace",
         };
-        
+
         tracing_subscriber::fmt()
             .with_env_filter(EnvFilter::from_default_env().add_directive(log_level.parse()?))
             .init();
@@ -53,21 +53,21 @@ async fn main() -> Result<()> {
             .with_env_filter(EnvFilter::from_default_env().add_directive("off".parse()?))
             .init();
     }
-    
+
     if cli.headless || cli.verbose > 0 {
         info!("CM Dashboard starting with individual metrics architecture...");
     }
-    
+
     // Create and run dashboard
     let mut dashboard = Dashboard::new(cli.config, cli.headless).await?;
-    
+
     // Setup graceful shutdown
     let ctrl_c = async {
         tokio::signal::ctrl_c()
             .await
             .expect("failed to install Ctrl+C handler");
     };
-    
+
     // Run dashboard with graceful shutdown
     tokio::select! {
         result = dashboard.run() => {
@@ -80,9 +80,9 @@ async fn main() -> Result<()> {
             info!("Shutdown signal received");
         }
     }
-    
+
     if cli.headless || cli.verbose > 0 {
         info!("Dashboard shutdown complete");
     }
     Ok(())
-}
+}