update database

lib/features/quotes/domain/entities/quote_item.dart

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+/// Domain Entity: Quote Item
+///
+/// Represents a single line item in a quotation.
+library;
+
+/// Quote Item Entity
+///
+/// Contains item-level information in a quote:
+/// - Product reference
+/// - Quantity and pricing
+/// - Price negotiation
+/// - Discounts
+class QuoteItem {
+  /// Unique quote item identifier
+  final String quoteItemId;
+
+  /// Quote ID this item belongs to
+  final String quoteId;
+
+  /// Product ID
+  final String productId;
+
+  /// Quantity quoted
+  final double quantity;
+
+  /// Original/list price per unit
+  final double originalPrice;
+
+  /// Negotiated price per unit
+  final double negotiatedPrice;
+
+  /// Discount percentage
+  final double discountPercent;
+
+  /// Subtotal (quantity * negotiatedPrice)
+  final double subtotal;
+
+  /// Item notes
+  final String? notes;
+
+  const QuoteItem({
+    required this.quoteItemId,
+    required this.quoteId,
+    required this.productId,
+    required this.quantity,
+    required this.originalPrice,
+    required this.negotiatedPrice,
+    required this.discountPercent,
+    required this.subtotal,
+    this.notes,
+  });
+
+  /// Calculate subtotal at original price
+  double get subtotalAtOriginalPrice => quantity * originalPrice;
+
+  /// Calculate discount amount per unit
+  double get discountPerUnit => originalPrice - negotiatedPrice;
+
+  /// Calculate total discount amount
+  double get totalDiscountAmount =>
+      (quantity * originalPrice) - (quantity * negotiatedPrice);
+
+  /// Calculate effective discount percentage
+  double get effectiveDiscountPercentage {
+    if (originalPrice == 0) return 0;
+    return ((originalPrice - negotiatedPrice) / originalPrice) * 100;
+  }
+
+  /// Check if item has discount
+  bool get hasDiscount => negotiatedPrice < originalPrice;
+
+  /// Check if price was negotiated
+  bool get isNegotiated => negotiatedPrice != originalPrice;
+
+  /// Copy with method for immutability
+  QuoteItem copyWith({
+    String? quoteItemId,
+    String? quoteId,
+    String? productId,
+    double? quantity,
+    double? originalPrice,
+    double? negotiatedPrice,
+    double? discountPercent,
+    double? subtotal,
+    String? notes,
+  }) {
+    return QuoteItem(
+      quoteItemId: quoteItemId ?? this.quoteItemId,
+      quoteId: quoteId ?? this.quoteId,
+      productId: productId ?? this.productId,
+      quantity: quantity ?? this.quantity,
+      originalPrice: originalPrice ?? this.originalPrice,
+      negotiatedPrice: negotiatedPrice ?? this.negotiatedPrice,
+      discountPercent: discountPercent ?? this.discountPercent,
+      subtotal: subtotal ?? this.subtotal,
+      notes: notes ?? this.notes,
+    );
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+
+    return other is QuoteItem &&
+        other.quoteItemId == quoteItemId &&
+        other.quoteId == quoteId &&
+        other.productId == productId &&
+        other.quantity == quantity &&
+        other.originalPrice == originalPrice &&
+        other.negotiatedPrice == negotiatedPrice &&
+        other.subtotal == subtotal;
+  }
+
+  @override
+  int get hashCode {
+    return Object.hash(
+      quoteItemId,
+      quoteId,
+      productId,
+      quantity,
+      originalPrice,
+      negotiatedPrice,
+      subtotal,
+    );
+  }
+
+  @override
+  String toString() {
+    return 'QuoteItem(quoteItemId: $quoteItemId, productId: $productId, '
+        'quantity: $quantity, originalPrice: $originalPrice, '
+        'negotiatedPrice: $negotiatedPrice, subtotal: $subtotal)';
+  }
+}