Fix empty disk mount detection

internal/watcher/watcher.go

@@ -5,6 +5,7 @@ import (
 	"os"
 	"path/filepath"
 	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -122,14 +123,15 @@ func (w *Watcher) probe() {
 }
 
 func discoverDisks(root string) map[string]disk.DiskInfo {
+	disks := make(map[string]disk.DiskInfo)
+
 	entries, err := os.ReadDir(root)
 	if err != nil {
-		return map[string]disk.DiskInfo{}
+		return disks
 	}
 
-	disks := make(map[string]disk.DiskInfo)
 	for _, entry := range entries {
-		if !entry.IsDir() {
+		if !entry.IsDir() || strings.HasPrefix(entry.Name(), ".") {
 			continue
 		}
 		mountPath := filepath.Join(root, entry.Name())
@@ -139,5 +141,12 @@ func discoverDisks(root string) map[string]disk.DiskInfo {
 		}
 		disks[mountPath] = info
 	}
+
+	// If no child mountpoints were detected, the disk may be mounted directly at root.
+	if len(disks) == 0 {
+		if info, _ := disk.Probe(root); info.State != disk.DiskAbsent {
+			disks[root] = info
+		}
+	}
 	return disks
 }