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/YearOverYearChartView.swift

@@ -3,6 +3,8 @@ import Charts
 
 struct YearOverYearChartView: View {
     @ObservedObject var viewModel: ChartsViewModel
+    /// Hidden when the host (e.g. a dashboard card) already shows a title.
+    var showsTitle: Bool = true
     @State private var selectedMonthIdx: Int?
 
     private let monthAbbreviations = ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
@@ -20,8 +22,10 @@ struct YearOverYearChartView: View {
 
     var body: some View {
         VStack(alignment: .leading, spacing: 16) {
-            Text(String(localized: "chart_yoy_title"))
-                .font(.headline)
+            if showsTitle {
+                Text(String(localized: "chart_yoy_title"))
+                    .font(.headline)
+            }
 
             if allYears.isEmpty {
                 Text(String(localized: "chart_yoy_empty"))