1.6.0 #6+#7: proyección/ETA de objetivos + insights inteligentes

Goal ETA (#6): GoalProjection engine (CAGR mensual robusto de la evolución +
aportaciones, proyecta mes a mes → fecha estimada, estado ahead/on-track/behind/
unreachable, sparkline). GoalsView muestra 'Projected: <mes>', chip de ritmo con color,
fallback 'Add contributions to reach this'. GoalsViewModel.projection(for:) cacheado.

Insights (#7): InsightsEngine rule-based on-device (sin red/AI). Reglas: allocation vs
target, riesgo de concentración, mejor/peor categoría, diversificación, racha, YTD,
ganancias, forecast, proximidad a milestone. Priorizados por tono, top 4. PortfolioInsight
gana detail + tone. Surface en el Dashboard.

Localización: 19 claves nuevas en los 7 idiomas.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L2p3gUZRNWW388rWFRjiU7

PortfolioJournal/Models/PortfolioInsight.swift

@@ -1,9 +1,47 @@
 import SwiftUI
 
+/// Tone / severity of an insight, used to pick an accent color and to
+/// prioritize which insights are surfaced first.
+enum InsightTone {
+    case positive
+    case neutral
+    case attention
+
+    /// Higher priority insights are shown first when capping the list.
+    var priority: Int {
+        switch self {
+        case .attention: return 2
+        case .positive: return 1
+        case .neutral: return 0
+        }
+    }
+}
+
 struct PortfolioInsight: Identifiable {
     let id: String
     let systemImage: String
     let title: String
     let value: String
     let accentColor: Color
+    /// Optional supporting line shown under the value in the richer card.
+    let detail: String?
+    let tone: InsightTone
+
+    init(
+        id: String,
+        systemImage: String,
+        title: String,
+        value: String,
+        accentColor: Color,
+        detail: String? = nil,
+        tone: InsightTone = .neutral
+    ) {
+        self.id = id
+        self.systemImage = systemImage
+        self.title = title
+        self.value = value
+        self.accentColor = accentColor
+        self.detail = detail
+        self.tone = tone
+    }
 }