2.0: banner export solo en semana completa + compartir desde toolbar

- El banner "ready to export" ya no aparece con la semana incompleta; solo
  cuando no quedan slots vacíos (y sigue siendo descartable con la X).
- Se añade un icono de compartir en la toolbar (cuando hay algo planificado)
  para no perder el acceso a exportar en semanas parciales; misma lógica de
  premium/paywall que el banner.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01A3HaWmmtTQ1vdTERtSYU6p

MealMood/Views/Home/HomeView.swift

@@ -202,6 +202,15 @@ struct HomeView: View {
                     HStack(spacing: 10) {
                         if let settings = settings,
                            let plan = fetchWeekPlan(for: viewModel.currentWeekStart) {
+                            if plan.slotList.contains(where: { $0.dishId != nil || $0.isEatingOut }) {
+                                Button {
+                                    requestWeekShare(plan: plan, settings: settings)
+                                } label: {
+                                    Image(systemName: "square.and.arrow.up")
+                                        .foregroundColor(.mealMoodTextPrimary)
+                                }
+                                .accessibilityLabel(Text("share_week_button"))
+                            }
                             if viewModel.canEditCurrentWeek {
                                 Button {
                                     viewModel.autoComplete(plan: plan, dishes: dishes, tags: tags, settings: settings, allPlans: weekPlans)
@@ -330,7 +339,10 @@ struct HomeView: View {
                     }
 
                     let filledCount = plan.slotList.filter { $0.dishId != nil || $0.isEatingOut }.count
-                    if filledCount > 0 && !isExportCalloutDismissed(plan) {
+                    let emptyCount = plan.slotList.filter { $0.dishId == nil && !$0.isEatingOut }.count
+                    // Only surface the export banner once the week is actually
+                    // complete (no empty slots) — and let the user dismiss it.
+                    if filledCount > 0 && emptyCount == 0 && !isExportCalloutDismissed(plan) {
                         exportCallout(plan: plan, settings: settings)
                     }
 
@@ -338,7 +350,6 @@ struct HomeView: View {
                         weekRatingRow(plan: plan)
                     }
 
-                    let emptyCount = plan.slotList.filter { $0.dishId == nil && !$0.isEatingOut }.count
                     if viewModel.canEditCurrentWeek && !dishes.isEmpty && emptyCount > 0 {
                         autoAssignBanner(emptyCount: emptyCount, plan: plan, settings: settings)
                     }
@@ -1013,6 +1024,17 @@ struct HomeView: View {
         )
     }
 
+    /// Entry point for the toolbar share action: premium shares directly, free
+    /// is routed to the paywall (same gating as the export banner).
+    private func requestWeekShare(plan: WeekPlan, settings: AppSettings) {
+        if settings.isPremium {
+            startShareFlow(plan: plan, settings: settings)
+        } else {
+            paywallSource = "share_week"
+            showPremiumFromExport = true
+        }
+    }
+
     private func startShareFlow(plan: WeekPlan, settings: AppSettings) {
         if settings.weekExportStyle == nil {
             pendingExportPlan = plan