Dashboard: quitar títulos duplicados en cards de gráficas (build 81) #33

showsTitle (default true) en HorizontalPerformanceChart, DrawdownChart,
VolatilityChartView, PredictionChartView y YearOverYearChartView; el
pageContent del Dashboard pasa false porque el header de la card ya nombra
la página. La sección Charts no cambia.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L38583J7AYWCVPevkivscj

PortfolioJournal/Views/Charts/PredictionChartView.swift

@@ -4,6 +4,8 @@ import Charts
 struct PredictionChartView: View {
     let predictions: [Prediction]
     let historicalData: [(date: Date, value: Decimal)]
+    /// Hidden when the host (e.g. a dashboard card) already shows a title.
+    var showsTitle: Bool = true
     @State private var selectedDate: Date?
     @Environment(\.horizontalSizeClass) private var labelsSizeClass
 
@@ -23,8 +25,10 @@ struct PredictionChartView: View {
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
             HStack {
-                Text(predictions.isEmpty ? "Prediction" : "\(predictions.count)-Month Prediction")
-                    .font(.headline)
+                if showsTitle {
+                    Text(predictions.isEmpty ? "Prediction" : "\(predictions.count)-Month Prediction")
+                        .font(.headline)
+                }
 
                 Spacer()