Remove Add Transaction feature and clean all related code

Deleted files:
- AddTransactionView.swift
- TransactionRepository.swift
- Transaction+CoreDataClass.swift

Cleaned files:
- SourceDetailViewModel: removed transactions published property,
  showingAddTransaction flag, transactionRepository dependency,
  addTransaction() and deleteTransaction() methods
- SourceDetailView: removed transactionsSection, TransactionRow struct,
  Add Transaction button from quickActions, sheet presentation
- InvestmentSource+CoreDataClass: removed transactions NSManaged property,
  transactionsArray, totalInvested, totalDividends, totalFees computed
  properties, and all transaction Core Data accessors
- SettingsViewModel: removed "Transaction" from resetAllData entity list
- SampleDataService: removed transactionRepository and sample transaction

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

PortfolioJournal/Utilities/Extensions/Color+Extensions.swift

@@ -105,6 +105,28 @@ extension Color {
         return Color(hex: hex) ?? .blue
     }
 
+    // MARK: - Source Colors (distinct per-source palette, different order from categories)
+
+    static let sourceColors: [String] = [
+        "#6366F1", // Indigo
+        "#F97316", // Orange
+        "#06B6D4", // Cyan
+        "#EF4444", // Red
+        "#84CC16", // Lime
+        "#EC4899", // Pink
+        "#14B8A6", // Teal
+        "#F59E0B", // Amber
+        "#8B5CF6", // Purple
+        "#3B82F6", // Blue
+        "#A855F7", // Violet
+        "#10B981", // Green
+    ]
+
+    static func sourceColor(at index: Int) -> Color {
+        let hex = sourceColors[index % sourceColors.count]
+        return Color(hex: hex) ?? .blue
+    }
+
     // MARK: - Chart Colors
 
     static let chartColors: [Color] = categoryColors.compactMap { Color(hex: $0) }

PortfolioJournal/Utilities/Extensions/Date+Extensions.swift

@@ -136,6 +136,18 @@ extension Date {
         return formatter.localizedString(for: self, relativeTo: Date())
     }
 
+    var relativeDayDescription: String {
+        let calendar = Calendar.current
+        let days = calendar.dateComponents([.day], from: calendar.startOfDay(for: self), to: calendar.startOfDay(for: Date())).day ?? 0
+        if days == 0 { return String(localized: "date_today") }
+        if days == 1 { return "1d ago" }
+        if days < 31 { return "\(days)d ago" }
+        let months = calendar.dateComponents([.month], from: self, to: Date()).month ?? 0
+        if months < 12 { return "\(max(1, months))mo ago" }
+        let years = calendar.dateComponents([.year], from: self, to: Date()).year ?? 0
+        return "\(max(1, years))y ago"
+    }
+
     var friendlyDescription: String {
         if isToday {
             return String(localized: "date_today")