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/Data/AppDbContext.cs

@@ -0,0 +1,71 @@
+using Microsoft.EntityFrameworkCore;
+using MealPlanner.Models;
+
+namespace MealPlanner.Data;
+
+public class AppDbContext(DbContextOptions<AppDbContext> options) : DbContext(options)
+{
+    public DbSet<Recipe> Recipes => Set<Recipe>();
+    public DbSet<RecipeIngredient> RecipeIngredients => Set<RecipeIngredient>();
+    public DbSet<MealPlan> MealPlans => Set<MealPlan>();
+    public DbSet<MealPlanEntry> MealPlanEntries => Set<MealPlanEntry>();
+    public DbSet<UserSettings> UserSettings => Set<UserSettings>();
+    public DbSet<CheckedShoppingItem> CheckedShoppingItems => Set<CheckedShoppingItem>();
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        base.OnModelCreating(modelBuilder);
+
+        // Recipe
+        modelBuilder.Entity<Recipe>(e =>
+        {
+            e.HasKey(r => r.Id);
+            e.HasIndex(r => r.UserId);
+            e.HasIndex(r => r.ExternalId);
+            e.HasMany(r => r.Ingredients)
+             .WithOne(i => i.Recipe)
+             .HasForeignKey(i => i.RecipeId)
+             .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        // RecipeIngredient
+        modelBuilder.Entity<RecipeIngredient>(e =>
+        {
+            e.HasKey(i => i.Id);
+        });
+
+        // MealPlan
+        modelBuilder.Entity<MealPlan>(e =>
+        {
+            e.HasKey(p => p.Id);
+            e.HasIndex(p => new { p.UserId, p.WeekStart }).IsUnique();
+            e.HasMany(p => p.Entries)
+             .WithOne(en => en.MealPlan)
+             .HasForeignKey(en => en.MealPlanId)
+             .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        // MealPlanEntry
+        modelBuilder.Entity<MealPlanEntry>(e =>
+        {
+            e.HasKey(en => en.Id);
+            e.HasOne(en => en.Recipe)
+             .WithMany()
+             .HasForeignKey(en => en.RecipeId)
+             .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        // UserSettings
+        modelBuilder.Entity<UserSettings>(e =>
+        {
+            e.HasKey(s => s.UserId);
+        });
+
+        // CheckedShoppingItem
+        modelBuilder.Entity<CheckedShoppingItem>(e =>
+        {
+            e.HasKey(c => c.Id);
+            e.HasIndex(c => new { c.MealPlanId, c.UserId, c.ItemName });
+        });
+    }
+}