reglas: el panel explica que se incumple y como arreglarlo; stats por etiqueta

- RuleViolation.reasons: el motor devuelve ahora QUE regla rompe cada
  asignacion (repetido en la semana, maximo por semana superado, no
  consecutivo, no mismo dia, solo comida/cena, solo entre semana o fin
  de semana) con su etiqueta y limite
- Panel de avisos: bloque con cada regla rota en lenguaje claro + una
  sugerencia de que hacer, y boton nuevo "Cambiar plato" que abre el
  selector de ese hueco (antes solo se podia quitar o ignorar)
- Estadisticas: matriz "Etiquetas por tipo de comida" (p.ej. cuantas
  cenas son de pescado) y "Platos por etiqueta" del catalogo
- Tests: 4 casos de las razones de incumplimiento; harness que renderiza
  las secciones nuevas de stats a /tmp/stats_render.png
- Strings en 6 idiomas

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_013H6bXqGX1ygwib1Dm3n3UG

MealMood/Views/Stats/StatsView.swift

@@ -15,6 +15,8 @@ struct StatsView: View {
                     summaryGrid
                     topDishesSection
                     tagBreakdownSection
+                    tagByMealSection
+                    dishesPerTagSection
                 }
                 .padding(.horizontal, 16)
                 .padding(.vertical, 20)
@@ -190,7 +192,7 @@ struct StatsView: View {
             .map { $0 }
     }
 
-    private struct TagEntry { let tag: Tag; let count: Int }
+    struct TagEntry { let tag: Tag; let count: Int }
 
     private var tagUsage: [TagEntry] {
         let dishMap = Dictionary(allDishes.map { ($0.id, $0) }, uniquingKeysWith: { first, _ in first })
@@ -212,6 +214,141 @@ struct StatsView: View {
     }
 }
 
+// Internal (not private) so the render harness in the tests can draw these
+// sections on their own — ImageRenderer cannot draw the NavigationStack body.
+extension StatsView {
+
+    /// Tag usage split by meal type — "how many dinners are pasta?".
+    var tagByMealSection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            Text("stats_tag_by_meal_title")
+                .font(.mealMoodH3)
+                .foregroundColor(.mealMoodTextPrimary)
+
+            if tagMealMatrix.isEmpty {
+                Text("stats_no_data")
+                    .font(.mealMoodBody)
+                    .foregroundColor(.mealMoodTextSecondary)
+                    .frame(maxWidth: .infinity, alignment: .center)
+                    .padding(.vertical, 16)
+            } else {
+                VStack(spacing: 0) {
+                    HStack {
+                        Text("").frame(maxWidth: .infinity, alignment: .leading)
+                        ForEach(usedMealTypes, id: \.self) { meal in
+                            Text(LocalizedStringKey(meal.localizedKey))
+                                .font(.mealMoodCaption.weight(.semibold))
+                                .foregroundColor(.mealMoodTextSecondary)
+                                .frame(width: 62)
+                        }
+                    }
+                    .padding(.horizontal, 12)
+                    .padding(.vertical, 8)
+
+                    ForEach(tagMealMatrix, id: \.tag.id) { row in
+                        Divider().padding(.leading, 12)
+                        HStack {
+                            HStack(spacing: 6) {
+                                TagDot(color: row.tag.color, size: 8)
+                                Text(row.tag.localizedName(language: language))
+                                    .font(.mealMoodSmall)
+                                    .foregroundColor(.mealMoodTextPrimary)
+                                    .lineLimit(1)
+                            }
+                            .frame(maxWidth: .infinity, alignment: .leading)
+
+                            ForEach(usedMealTypes, id: \.self) { meal in
+                                Text("\(row.counts[meal] ?? 0)")
+                                    .font(.mealMoodSmall.weight(.semibold))
+                                    .foregroundColor((row.counts[meal] ?? 0) > 0 ? .mealMoodTextPrimary : .mealMoodTextSecondary.opacity(0.5))
+                                    .frame(width: 62)
+                            }
+                        }
+                        .padding(.horizontal, 12)
+                        .padding(.vertical, 10)
+                    }
+                }
+                .background(Color.mealMoodSurface)
+                .clipShape(RoundedRectangle(cornerRadius: 12))
+            }
+        }
+    }
+
+    /// How many dishes in the catalogue carry each tag.
+    var dishesPerTagSection: some View {
+        VStack(alignment: .leading, spacing: 12) {
+            Text("stats_dishes_per_tag_title")
+                .font(.mealMoodH3)
+                .foregroundColor(.mealMoodTextPrimary)
+
+            if dishesPerTag.isEmpty {
+                Text("stats_no_data")
+                    .font(.mealMoodBody)
+                    .foregroundColor(.mealMoodTextSecondary)
+                    .frame(maxWidth: .infinity, alignment: .center)
+                    .padding(.vertical, 16)
+            } else {
+                VStack(spacing: 10) {
+                    ForEach(dishesPerTag, id: \.tag.id) { entry in
+                        TagBarRow(
+                            tagName: entry.tag.localizedName(language: language),
+                            tagColor: entry.tag.color,
+                            count: entry.count,
+                            maxCount: dishesPerTag.first?.count ?? 1
+                        )
+                    }
+                }
+                .padding(14)
+                .background(Color.mealMoodSurface)
+                .clipShape(RoundedRectangle(cornerRadius: 12))
+            }
+        }
+    }
+
+    var usedMealTypes: [MealType] {
+        let raw = Set(weekPlans.flatMap { $0.slotList.map(\.mealType) })
+        let types = MealType.allCases.filter { raw.contains($0.rawValue) }
+        return types.isEmpty ? [.lunch, .dinner] : types
+    }
+
+    struct TagMealRow { let tag: Tag; let counts: [MealType: Int]; let total: Int }
+
+    var tagMealMatrix: [TagMealRow] {
+        let dishMap = Dictionary(allDishes.map { ($0.id, $0) }, uniquingKeysWith: { first, _ in first })
+        var counts: [UUID: [MealType: Int]] = [:]
+        for plan in weekPlans {
+            for slot in plan.slotList {
+                guard let meal = MealType(rawValue: slot.mealType) else { continue }
+                for dishId in [slot.dishId, slot.secondaryDishId].compactMap({ $0 }) {
+                    guard let dish = dishMap[dishId] else { continue }
+                    for tagId in dish.tagIds {
+                        counts[tagId, default: [:]][meal, default: 0] += 1
+                    }
+                }
+            }
+        }
+        return counts.compactMap { tagId, byMeal -> TagMealRow? in
+            guard let tag = allTags.first(where: { $0.id == tagId }) else { return nil }
+            return TagMealRow(tag: tag, counts: byMeal, total: byMeal.values.reduce(0, +))
+        }
+        .sorted { $0.total > $1.total }
+        .prefix(8)
+        .map { $0 }
+    }
+
+    var dishesPerTag: [TagEntry] {
+        var counts: [UUID: Int] = [:]
+        for dish in allDishes {
+            for tagId in dish.tagIds { counts[tagId, default: 0] += 1 }
+        }
+        return counts
+            .compactMap { id, count in allTags.first(where: { $0.id == id }).map { TagEntry(tag: $0, count: count) } }
+            .sorted { $0.count > $1.count }
+            .prefix(8)
+            .map { $0 }
+    }
+}
+
 // MARK: - Sub-views
 
 private struct StatCard: View {