adds syncing

lib/models/supplement_intake.dart

@@ -1,3 +1,7 @@
+import 'package:uuid/uuid.dart';
+
+import 'sync_enums.dart';
+
 class SupplementIntake {
   final int? id;
   final int supplementId;
@@ -6,6 +10,12 @@ class SupplementIntake {
   final double unitsTaken; // Number of units taken (can be fractional)
   final String? notes;
 
+  // Sync metadata
+  final String syncId;
+  final DateTime lastModified;
+  final SyncStatus syncStatus;
+  final bool isDeleted;
+
   SupplementIntake({
     this.id,
     required this.supplementId,
@@ -13,7 +23,12 @@ class SupplementIntake {
     required this.dosageTaken,
     required this.unitsTaken,
     this.notes,
-  });
+    String? syncId,
+    DateTime? lastModified,
+    this.syncStatus = SyncStatus.pending,
+    this.isDeleted = false,
+  }) : syncId = syncId ?? const Uuid().v4(),
+       lastModified = lastModified ?? DateTime.now();
 
   Map<String, dynamic> toMap() {
     return {
@@ -23,6 +38,10 @@ class SupplementIntake {
       'dosageTaken': dosageTaken,
       'unitsTaken': unitsTaken,
       'notes': notes,
+      'syncId': syncId,
+      'lastModified': lastModified.toIso8601String(),
+      'syncStatus': syncStatus.name,
+      'isDeleted': isDeleted ? 1 : 0,
     };
   }
 
@@ -34,6 +53,17 @@ class SupplementIntake {
       dosageTaken: map['dosageTaken'],
       unitsTaken: (map['unitsTaken'] ?? 1).toDouble(), // Default for backwards compatibility
       notes: map['notes'],
+      syncId: map['syncId'] ?? const Uuid().v4(),
+      lastModified: map['lastModified'] != null
+          ? DateTime.parse(map['lastModified'])
+          : DateTime.now(),
+      syncStatus: map['syncStatus'] != null
+          ? SyncStatus.values.firstWhere(
+              (e) => e.name == map['syncStatus'],
+              orElse: () => SyncStatus.pending,
+            )
+          : SyncStatus.pending,
+      isDeleted: (map['isDeleted'] ?? 0) == 1,
     );
   }
 
@@ -44,6 +74,10 @@ class SupplementIntake {
     double? dosageTaken,
     double? unitsTaken,
     String? notes,
+    String? syncId,
+    DateTime? lastModified,
+    SyncStatus? syncStatus,
+    bool? isDeleted,
   }) {
     return SupplementIntake(
       id: id ?? this.id,
@@ -52,6 +86,26 @@ class SupplementIntake {
       dosageTaken: dosageTaken ?? this.dosageTaken,
       unitsTaken: unitsTaken ?? this.unitsTaken,
       notes: notes ?? this.notes,
+      syncId: syncId ?? this.syncId,
+      lastModified: lastModified ?? this.lastModified,
+      syncStatus: syncStatus ?? this.syncStatus,
+      isDeleted: isDeleted ?? this.isDeleted,
+    );
+  }
+
+  /// Create a new intake marked as synced
+  SupplementIntake markAsSynced() {
+    return copyWith(
+      syncStatus: SyncStatus.synced,
+    );
+  }
+
+  /// Create a new intake marked for deletion
+  SupplementIntake markAsDeleted() {
+    return copyWith(
+      isDeleted: true,
+      lastModified: DateTime.now(),
+      syncStatus: SyncStatus.modified,
     );
   }
 }