Fix SnapRAID parity association using directory-based discovery

- Replace blanket parity drive inclusion with smart relationship detection
- Only associate parity drives from same parent directory as data drives
- Prevent incorrect exclusion of nvme0n1 physical drives from grouping
- Maintain zero-configuration auto-discovery without hardcoded paths

agent/src/collectors/disk.rs

@@ -218,9 +218,9 @@ impl DiskCollector {
                     raw_paths
                 };
                 
-                // For SnapRAID setups, also include parity drives as part of the pool
-                let snapraid_parity_paths = self.discover_snapraid_parity_drives()?;
-                member_paths.extend(snapraid_parity_paths);
+                // For SnapRAID setups, include parity drives that are related to this pool's data drives
+                let related_parity_paths = self.discover_related_parity_drives(&member_paths)?;
+                member_paths.extend(related_parity_paths);
                 
                 // Categorize as data vs parity drives
                 let (data_drives, parity_drives) = match self.categorize_pool_drives(&member_paths) {
@@ -244,14 +244,36 @@ impl DiskCollector {
         Ok(pools)
     }
 
-    /// Discover SnapRAID parity drives
-    fn discover_snapraid_parity_drives(&self) -> Result<Vec<String>> {
+    /// Discover parity drives that are related to the given data drives
+    fn discover_related_parity_drives(&self, data_drives: &[String]) -> Result<Vec<String>> {
         let mount_devices = self.get_mount_devices()?;
-        let parity_paths: Vec<String> = mount_devices.keys()
-            .filter(|path| path.contains("parity"))
-            .cloned()
-            .collect();
-        Ok(parity_paths)
+        let mut related_parity = Vec::new();
+        
+        // Find parity drives that share the same parent directory as the data drives
+        for data_path in data_drives {
+            if let Some(parent_dir) = self.get_parent_directory(data_path) {
+                // Look for parity drives in the same parent directory
+                for (mount_point, _device) in &mount_devices {
+                    if mount_point.contains("parity") && mount_point.starts_with(&parent_dir) {
+                        if !related_parity.contains(mount_point) {
+                            related_parity.push(mount_point.clone());
+                        }
+                    }
+                }
+            }
+        }
+        
+        Ok(related_parity)
+    }
+    
+    /// Get parent directory of a mount path (e.g., "/mnt/disk1" -> "/mnt")
+    fn get_parent_directory(&self, path: &str) -> Option<String> {
+        if let Some(last_slash) = path.rfind('/') {
+            if last_slash > 0 {
+                return Some(path[..last_slash].to_string());
+            }
+        }
+        None
     }
 
     /// Categorize pool member drives as data vs parity