fix: show 'Just now' instead of '1s ago' after refresh

Replaced RelativeDateTimeFormatter with manual formatting:
<5s → 'Just now', <60s → 'Xs ago', <1h → 'Xm ago',
<1d → 'Xh ago', else 'Xd ago'.

Co-Authored-By: Claude <noreply@anthropic.com>

Sources/Views/MenuBar/BugListPopover.swift

@@ -110,9 +110,20 @@ struct BugListPopover: View {
     }
 
     private func formatted(_ date: Date) -> String {
-        let formatter = RelativeDateTimeFormatter()
-        formatter.unitsStyle = .abbreviated
-        return formatter.localizedString(for: date, relativeTo: Date())
+        let seconds = Int(Date().timeIntervalSince(date))
+        switch seconds {
+        case ..<5:   return "Just now"
+        case ..<60:  return "\(seconds)s ago"
+        case ..<3600:
+            let m = seconds / 60
+            return m == 1 ? "1m ago" : "\(m)m ago"
+        case ..<86400:
+            let h = seconds / 3600
+            return h == 1 ? "1h ago" : "\(h)h ago"
+        default:
+            let d = seconds / 86400
+            return d == 1 ? "1d ago" : "\(d)d ago"
+        }
     }
 }