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/DrawdownChart.swift

@@ -3,6 +3,8 @@ import Charts
 
 struct DrawdownChart: View {
     let data: [(date: Date, drawdown: Double)]
+    /// Hidden when the host (e.g. a dashboard card) already shows a title.
+    var showsTitle: Bool = true
     @State private var zoom = ChartZoomModel()
     @State private var selectedDate: Date?
     @Environment(\.horizontalSizeClass) private var labelsSizeClass
@@ -26,8 +28,10 @@ struct DrawdownChart: View {
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
             HStack {
-                Text("Drawdown Analysis")
-                    .font(.headline)
+                if showsTitle {
+                    Text("Drawdown Analysis")
+                        .font(.headline)
+                }
 
                 Spacer()
 
@@ -207,6 +211,8 @@ struct DrawdownStatView: View {
 
 struct VolatilityChartView: View {
     let data: [(date: Date, volatility: Double)]
+    /// Hidden when the host (e.g. a dashboard card) already shows a title.
+    var showsTitle: Bool = true
     @State private var zoom = ChartZoomModel()
     @State private var selectedDate: Date?
     @Environment(\.horizontalSizeClass) private var labelsSizeClass
@@ -230,11 +236,13 @@ struct VolatilityChartView: View {
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
-            HStack {
-                Text("Volatility")
-                    .font(.headline)
+            if showsTitle {
+                HStack {
+                    Text("Volatility")
+                        .font(.headline)
 
-                Spacer()
+                    Spacer()
+                }
             }
 
             Text("Measures price variability over time")