feat: Phase 4 - Offline & merge enhancements

- Added 'opal sync merge' command for initial database merge
- Support for merge strategies: prefer-local, prefer-server, smart (default)
- Offline queue already implemented in Phase 2
- Conflict warning display already implemented in Phase 2-3
- Full offline mode support with automatic queueing when server unreachable

opal-task/internal/engine/display.go

@@ -207,7 +207,7 @@ func formatStatus(status Status) string {
 	case StatusDeleted:
 		return color.RedString("deleted")
 	case StatusRecurring:
-		return color.BlueString("template")
+		return color.BlueString("recurring")
 	default:
 		return "unknown"
 	}