Feedback TestFlight build 58 (build 59): labels, needs-update, period selector, Home masonry

De 7 comentarios de TestFlight:
- Labels de línea ilegibles (puntos 5+7): ChartLabels.showsLabel thin-out
  (máx 5 iPhone / 8 iPad, siempre primero y último). Charts multi-serie
  (Compare, Period, Year vs Year) etiquetan solo el ENDPOINT de cada serie.
  Prediction etiqueta solo el forecast final. Aplicado a Evolution, Rolling,
  Drawdown, Volatility, Compare, Period, YoY, Prediction.
- 'Needs update' en meses pasados (punto 2): MonthlyCheckInView.snapshotForViewedMonth
  — el estado es por el MES QUE SE VE (effective month de referenceDate), no
  contra la última completion global. Diff usa el snapshot de ese mes.
- Selector de periodo Performance (punto 6): slider 1..60 → picker segmentado
  consistente con el resto, opciones capadas a los meses de datos disponibles
  (availableHistoryMonths). Ya no deja pedir ventanas sin datos.
- Home iPad/Mac (feedback previo): masonry con nº de columnas según ancho
  (2 iPad / 3 Mac ancho >=1250), reparto por peso, propio ScrollView.

Pendiente de este lote: Goals no sincronizan (verificado modelo Goal CloudKit-OK
→ es el subset del partial-failure, no filtro ni esquema; necesita códigos
internos del error), paste/OCR por campo (punto 3) y swipe entre charts (punto 4).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WoScpmHdVj1aUf4rAp6hbe

PortfolioJournal/Views/Charts/YearOverYearChartView.swift

@@ -93,8 +93,11 @@ struct YearOverYearChartView: View {
 
     // MARK: - Chart
 
-    /// Two selected years × 12 months stays readable with permanent labels.
-    private var showAllLabels: Bool { selectedSeries.count <= 2 }
+    /// Last month index that has data, per series id — label only that endpoint
+    /// (the year's cumulative return) to avoid 24 overlapping labels.
+    private func lastValidMonth(_ series: ChartsViewModel.YearSeries) -> Int? {
+        (0..<12).last { !series.values[$0].isNaN }
+    }
 
     private func selectionRows(for month: Int) -> [(label: String, value: String, color: Color)] {
         selectedSeries.compactMap { series in
@@ -113,6 +116,7 @@ struct YearOverYearChartView: View {
                     let idx = allYears.firstIndex(where: { $0.id == yearSeries.id }) ?? 0
                     let color = lineColors[idx % lineColors.count]
                     let seriesPosition = selectedSeries.firstIndex(where: { $0.id == yearSeries.id }) ?? 0
+                    let endMonth = lastValidMonth(yearSeries)
                     ForEach(0..<12, id: \.self) { monthIdx in
                         let value = yearSeries.values[monthIdx]
                         if !value.isNaN {
@@ -129,9 +133,9 @@ struct YearOverYearChartView: View {
                                 y: .value("Return", value)
                             )
                             .foregroundStyle(color)
-                            .symbolSize(showAllLabels ? 32 : 18)
+                            .symbolSize(monthIdx == endMonth ? 34 : 18)
                             .annotation(position: seriesPosition == 0 ? .top : .bottom, spacing: 2) {
-                                if showAllLabels {
+                                if monthIdx == endMonth {
                                     ChartValueBubble(text: ChartLabels.percent(value), color: color)
                                 }
                             }