1.4.1 (build 42): contribución por snapshot, fixes Period vs Period y navegación iPad

- 151: contribución editable por snapshot en cualquier modo (quitado gate detailed)
  con diálogo de propagación al editar: solo este / adelante / atrás / todos
  (SnapshotRepository.propagateContribution, SnapshotFormViewModel.contributionChanged)
- 148: Period vs Period mostraba mal el último mes del period B — la agrupación usaba
  chartMonth(for:) que aplicaba el grace-period del check-in a snapshots históricos;
  ahora agrupa por mes calendario crudo
- 152: iPad Sources no saltaba entre fuentes — añadido .id() al SourceDetailView para
  recrear el StateObject al cambiar de selección
- 146/147: Year vs Year con forecast del año en curso (asterisco de estimado) y KPIs
  arriba / detalle debajo
- 145: card de contribución mensual en SourceDetailView
- Nuevas claves snapshot_contribution_propagate_* en los 7 idiomas

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015qUZrBusG82T37R7PeokqJ

PortfolioJournal/Views/Charts/ComparisonChartView.swift

@@ -4,7 +4,6 @@ import Charts
 struct ComparisonChartView: View {
     @ObservedObject var viewModel: ChartsViewModel
 
-    private let palette: [Color] = [.blue, .orange, .green, .purple, .red, .teal]
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
@@ -35,7 +34,7 @@ struct ComparisonChartView: View {
             HStack(spacing: 8) {
                 ForEach(Array(viewModel.comparisonAvailableSources.enumerated()), id: \.element.id) { index, source in
                     let isSelected = viewModel.comparisonSelectedSourceIds.contains(source.id)
-                    let chipColor = palette[index % palette.count]
+                    let chipColor = Color(hex: ChartsViewModel.sourceColorHexesPublic[index % ChartsViewModel.sourceColorHexesPublic.count]) ?? .appPrimary
                     Button {
                         if isSelected {
                             viewModel.comparisonSelectedSourceIds.remove(source.id)
@@ -106,8 +105,8 @@ struct ComparisonChartView: View {
     private var lineChart: some View {
         VStack(spacing: 12) {
             Chart {
-                ForEach(Array(viewModel.comparisonData.enumerated()), id: \.element.id) { index, series in
-                    let seriesColor = palette[index % palette.count]
+                ForEach(viewModel.comparisonData, id: \.id) { series in
+                    let seriesColor = Color(hex: series.colorHex) ?? .appPrimary
                     ForEach(series.points, id: \.date) { point in
                         LineMark(
                             x: .value("Date", point.date),
@@ -149,10 +148,10 @@ struct ComparisonChartView: View {
     private var legend: some View {
         ScrollView(.horizontal, showsIndicators: false) {
             HStack(spacing: 16) {
-                ForEach(Array(viewModel.comparisonData.enumerated()), id: \.element.id) { index, series in
+                ForEach(viewModel.comparisonData, id: \.id) { series in
                     HStack(spacing: 6) {
                         RoundedRectangle(cornerRadius: 2)
-                            .fill(palette[index % palette.count])
+                            .fill(Color(hex: series.colorHex) ?? .appPrimary)
                             .frame(width: 20, height: 3)
                         Text(series.name)
                             .font(.caption)
@@ -183,6 +182,8 @@ struct ComparisonChartView: View {
             return String(format: "%.1f%%", value)
         case .absolute:
             return Decimal(value).shortCurrencyString
+        case .monthlyReturn:
+            return String(format: "%.1f%%", value)
         }
     }
 }