export: revision UX de estilos, 2 estilos nuevos y copia como texto

- Header elegante: logo fijado a la izquierda y titulo centrado de verdad
  (ZStack), fecha a la derecha
- School transpuesto: dias como columnas y comidas como filas — antes con
  1-2 comidas quedaba media pagina A4 apaisada en blanco
- Default: las celdas del grid se expanden para llenar la pagina (mismo
  sintoma de hueco que el school)
- Estilo nuevo "Story" (9:16, 2160x3840) para stories de IG/WhatsApp y
  "Minimal (imprimir)" en A4 con lineas finas sin fondos (ahorro tinta)
- Picker del preview pasa de segmentado a chips desplazables (5 estilos)
- WeekPlanTextExporter + boton "Copiar como texto (WhatsApp)" en el
  preview: menu semanal con *negritas* y emojis listo para pegar en
  WhatsApp/Telegram (evento analytics format=text)
- Harness de render en tests: genera PNG de los 5 estilos con datos de
  ejemplo en /tmp/mealmood-export-previews para revisar el diseno
- Nombres de estilos en espanol corregidos (estaban en ingles)

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

MealMoodTests/DateHelpersTests.swift

@@ -1,6 +1,77 @@
 import XCTest
+import SwiftUI
+import SwiftData
 @testable import MealMood
 
+/// Not a real assertion suite: renders every export style with sample data to
+/// /tmp/mealmood-export-previews/ so design changes can be reviewed as images.
+final class ExportStyleRenderTests: XCTestCase {
+
+    @MainActor
+    func testRenderAllExportStyles() throws {
+        let config = ModelConfiguration(isStoredInMemoryOnly: true)
+        let container = try ModelContainer(
+            for: AppSettings.self, Dish.self, Tag.self, WeekPlan.self, MealSlot.self,
+            configurations: config
+        )
+        let context = container.mainContext
+
+        let settings = AppSettings()
+        settings.activeMealTypes = [.lunch, .dinner]
+        settings.includeWeekends = true
+        settings.language = "es"
+        context.insert(settings)
+
+        let names = [
+            "Tortilla de patatas", "Salmón al horno", "Ensalada César",
+            "Lentejas con chorizo", "Pizza casera", "Pollo asado con patatas",
+            "Crema de calabaza", "Espaguetis boloñesa", "Merluza en salsa verde",
+            "Arroz tres delicias", "Fajitas de pollo", "Gazpacho", "Croquetas caseras", "Sopa de fideos"
+        ]
+        let dishes = names.map { Dish(name: $0) }
+        dishes.forEach { context.insert($0) }
+
+        let monday = Calendar(identifier: .gregorian).date(from: DateComponents(year: 2026, month: 8, day: 31))!
+        let plan = WeekPlan(weekStartDate: monday)
+        context.insert(plan)
+        var dishIndex = 0
+        for day in 0...6 {
+            for meal in [MealType.lunch, .dinner] {
+                let slot = MealSlot(dayOfWeek: day, mealType: meal.rawValue)
+                if day == 5 && meal == .dinner {
+                    slot.isEatingOut = true
+                } else {
+                    slot.dishId = dishes[dishIndex % dishes.count].id
+                    if day == 2 && meal == .dinner {
+                        slot.secondaryDishId = dishes[(dishIndex + 5) % dishes.count].id
+                    }
+                    dishIndex += 1
+                }
+                slot.weekPlan = plan
+                plan.slotList.append(slot)
+                context.insert(slot)
+            }
+        }
+        try context.save()
+
+        let outputDir = URL(fileURLWithPath: "/tmp/mealmood-export-previews")
+        try? FileManager.default.createDirectory(at: outputDir, withIntermediateDirectories: true)
+
+        for style in WeekExportStyle.allCases {
+            let renderer = ImageRenderer(content: WeekPlanShareView(
+                plan: plan, settings: settings, dishes: dishes, tags: [],
+                exportStyleOverride: style
+            ))
+            let size = WeekPlanShareView.canvasSize(for: style)
+            renderer.proposedSize = ProposedViewSize(width: size.width, height: size.height)
+            renderer.scale = 1
+            let image = try XCTUnwrap(renderer.uiImage, "render failed for \(style.rawValue)")
+            let data = try XCTUnwrap(image.pngData())
+            try data.write(to: outputDir.appendingPathComponent("export-\(style.rawValue).png"))
+        }
+    }
+}
+
 final class DateHelpersTests: XCTestCase {
 
     func testStartOfWeekReturnsMonday() {