feat: Add settings provider for theme and time range management

- Implemented SettingsProvider to manage user preferences for theme options and time ranges for reminders.
- Added persistent reminder settings with configurable retry intervals and maximum attempts.
- Created UI for settings screen to allow users to customize their preferences.
- Integrated shared_preferences for persistent storage of user settings.

feat: Introduce Ingredient model

- Created Ingredient model to represent nutritional components with properties for id, name, amount, and unit.
- Added methods for serialization and deserialization of Ingredient objects.

feat: Develop Archived Supplements Screen

- Implemented ArchivedSupplementsScreen to display archived supplements with options to unarchive or delete.
- Added UI components for listing archived supplements and handling user interactions.

chore: Update dependencies in pubspec.yaml and pubspec.lock

- Updated shared_preferences dependency to the latest version.
- Removed flutter_datetime_picker_plus dependency and added file dependency.
- Updated Flutter SDK constraint to >=3.27.0.

lib/models/ingredient.dart

@@ -0,0 +1,64 @@
+class Ingredient {
+  final int? id;
+  final String name; // e.g., "Vitamin K2", "Vitamin D3"
+  final double amount; // e.g., 75, 20
+  final String unit; // e.g., "mcg", "mg", "IU"
+
+  const Ingredient({
+    this.id,
+    required this.name,
+    required this.amount,
+    required this.unit,
+  });
+
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'name': name,
+      'amount': amount,
+      'unit': unit,
+    };
+  }
+
+  factory Ingredient.fromMap(Map<String, dynamic> map) {
+    return Ingredient(
+      id: map['id'],
+      name: map['name'],
+      amount: map['amount']?.toDouble() ?? 0.0,
+      unit: map['unit'],
+    );
+  }
+
+  Ingredient copyWith({
+    int? id,
+    String? name,
+    double? amount,
+    String? unit,
+  }) {
+    return Ingredient(
+      id: id ?? this.id,
+      name: name ?? this.name,
+      amount: amount ?? this.amount,
+      unit: unit ?? this.unit,
+    );
+  }
+
+  @override
+  String toString() {
+    return '$amount$unit $name';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+    return other is Ingredient &&
+        other.name == name &&
+        other.amount == amount &&
+        other.unit == unit;
+  }
+
+  @override
+  int get hashCode {
+    return name.hashCode ^ amount.hashCode ^ unit.hashCode;
+  }
+}