Remove redundant smart collector - consolidate SMART into disk collector

- Remove separate smart collector implementation
- Disk collector already handles SMART data for drives
- Eliminates duplicate smartctl calls causing performance issues
- SMART functionality remains in logical place with disk monitoring
- Fixes infinite smartctl loop issue

agent/src/metrics/mod.rs

@@ -4,7 +4,7 @@ use tracing::{error, info};
 
 use crate::collectors::{
     backup::BackupCollector, cpu::CpuCollector, disk::DiskCollector, memory::MemoryCollector,
-    nixos::NixOSCollector, smart::SmartCollector, systemd::SystemdCollector, Collector,
+    nixos::NixOSCollector, systemd::SystemdCollector, Collector,
 };
 use crate::config::{AgentConfig, CollectorConfig};
 
@@ -61,14 +61,6 @@ impl MetricCollectionManager {
                     info!("BENCHMARK: Backup collector only");
                 }
             }
-            Some("smart") => {
-                // SMART collector only
-                if config.smart.enabled {
-                    let smart_collector = SmartCollector;
-                    collectors.push(Box::new(smart_collector));
-                    info!("BENCHMARK: SMART collector only");
-                }
-            }
             Some("none") => {
                 // No collectors - test agent loop only
                 info!("BENCHMARK: No collectors enabled");
@@ -110,11 +102,6 @@ impl MetricCollectionManager {
                     info!("NixOS collector initialized");
                 }
 
-                if config.smart.enabled {
-                    let smart_collector = SmartCollector;
-                    collectors.push(Box::new(smart_collector));
-                    info!("SMART collector initialized");
-                }
             }
         }