feat: complete mealplanner app (backend + frontend + deployment)

.NET 8 backend with Zitadel JWT auth, TheMealDB integration,
weekly meal plan generation, shopping list aggregation.
Vue 3 + Tailwind 4 frontend with dark emerald theme,
manual OIDC PKCE auth, all views implemented.
Multi-stage Dockerfile with nginx reverse proxy.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/Models/MealPlanEntry.cs

@@ -0,0 +1,12 @@
+namespace MealPlanner.Models;
+
+public class MealPlanEntry
+{
+    public Guid Id { get; set; }
+    public Guid MealPlanId { get; set; }
+    public DateOnly Date { get; set; }
+    public Guid RecipeId { get; set; }
+
+    public MealPlan MealPlan { get; set; } = null!;
+    public Recipe Recipe { get; set; } = null!;
+}