Display disk serial numbers instead of device names

- Add serial_number field to DriveData structure
- Collect serial numbers from SMART data for all drives
- Display truncated serial numbers (last 8 chars) in dashboard
- Fix parity drive label to show status icon before "Parity:"
- Fix mount point label styling to match other labels

dashboard/src/ui/widgets/system.rs

@@ -239,8 +239,11 @@ impl SystemWidget {
             };
 
             // Add drive info
+            let display_name = drive.serial_number.as_ref()
+                .map(|s| truncate_serial(s))
+                .unwrap_or(drive.name.clone());
             let storage_drive = StorageDrive {
-                name: drive.name.clone(),
+                name: display_name,
                 temperature: drive.temperature_celsius,
                 wear_percent: drive.wear_percent,
                 status: Status::Ok,
@@ -310,8 +313,10 @@ impl SystemWidget {
                 } else {
                     Status::Unknown
                 };
-                
-                let display_name = drive.serial_number.clone().unwrap_or(drive.name.clone());
+
+                let display_name = drive.serial_number.as_ref()
+                    .map(|s| truncate_serial(s))
+                    .unwrap_or(drive.name.clone());
                 let storage_drive = StorageDrive {
                     name: display_name,
                     temperature: drive.temperature_celsius,
@@ -333,8 +338,10 @@ impl SystemWidget {
                 } else {
                     Status::Unknown
                 };
-                
-                let display_name = drive.serial_number.clone().unwrap_or(drive.name.clone());
+
+                let display_name = drive.serial_number.as_ref()
+                    .map(|s| truncate_serial(s))
+                    .unwrap_or(drive.name.clone());
                 let storage_drive = StorageDrive {
                     name: display_name,
                     temperature: drive.temperature_celsius,
@@ -460,14 +467,13 @@ impl SystemWidget {
                         }
                         
                         let drive_text = if !drive_details.is_empty() {
-                            format!("{} {}", drive.name, drive_details.join(" "))
+                            format!("Parity: {} {}", drive.name, drive_details.join(" "))
                         } else {
-                            drive.name.clone()
+                            format!("Parity: {}", drive.name)
                         };
-                        
+
                         let mut parity_spans = vec![
                             Span::styled("  ├─ ", Typography::tree()),
-                            Span::styled("Parity: ", Typography::secondary()),
                         ];
                         parity_spans.extend(StatusIcons::create_status_spans(drive.status.clone(), &drive_text));
                         lines.push(Line::from(parity_spans));
@@ -476,7 +482,8 @@ impl SystemWidget {
 
                 // Mount point
                 lines.push(Line::from(vec![
-                    Span::styled("  └─ Mount: ", Typography::tree()),
+                    Span::styled("  └─ ", Typography::tree()),
+                    Span::styled("Mount: ", Typography::secondary()),
                     Span::styled(&pool.mount_point, Typography::secondary())
                 ]));
             }
@@ -486,6 +493,16 @@ impl SystemWidget {
     }
 }
 
+/// Truncate serial number to last 8 characters
+fn truncate_serial(serial: &str) -> String {
+    let len = serial.len();
+    if len > 8 {
+        serial[len - 8..].to_string()
+    } else {
+        serial.to_string()
+    }
+}
+
 /// Helper function to render a drive in a MergerFS pool
 fn render_mergerfs_drive<'a>(drive: &StorageDrive, tree_symbol: &'a str, lines: &mut Vec<Line<'a>>) {
     let mut drive_details = Vec::new();
@@ -542,6 +559,7 @@ impl SystemWidget {
 
         // First line: serial number with temperature and wear
         if let Some(serial) = &self.backup_disk_serial {
+            let truncated_serial = truncate_serial(serial);
             let mut details = Vec::new();
             if let Some(temp) = self.backup_disk_temperature {
                 details.push(format!("T: {}°C", temp as i32));
@@ -551,9 +569,9 @@ impl SystemWidget {
             }
 
             let disk_text = if !details.is_empty() {
-                format!("{} {}", serial, details.join(" "))
+                format!("{} {}", truncated_serial, details.join(" "))
             } else {
-                serial.clone()
+                truncated_serial
             };
 
             let backup_status = match self.backup_status.as_str() {