Add Status::Inactive for inactive services with empty circle display

- Add new Status::Inactive variant to enum for better service state representation
- Agent now assigns Status::Inactive instead of Status::Warning for inactive services
- Dashboard displays inactive services with empty circle (○) icon in gray color
- User-stopped services still show as Status::Ok with green filled circle
- Inactive services treated as OK for host status aggregation
- Improves visual clarity between active (●), inactive (○), and warning (◐) states

dashboard/src/ui/mod.rs

@@ -718,6 +718,7 @@ impl TuiApp {
                 Status::Warning => has_warning = true,
                 Status::Pending => has_pending = true,
                 Status::Ok => ok_count += 1,
+                Status::Inactive => ok_count += 1, // Treat inactive as OK for aggregation
                 Status::Unknown => {}, // Ignore unknown for aggregation
                 Status::Offline => {}, // Ignore offline for aggregation
             }