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>

Dockerfile

@@ -0,0 +1,33 @@
+# Stage 1: Build frontend
+FROM oven/bun:1 AS frontend-build
+WORKDIR /app
+COPY frontend/package.json frontend/bun.lock* ./
+RUN bun install --frozen-lockfile || bun install
+COPY frontend/ .
+RUN bun run build
+
+# Stage 2: Build backend
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS backend-build
+WORKDIR /src
+COPY backend/*.csproj .
+RUN dotnet restore
+COPY backend/ .
+RUN dotnet publish -c Release -o /app
+
+# Stage 3: Runtime
+FROM mcr.microsoft.com/dotnet/aspnet:8.0
+RUN apt-get update && apt-get install -y nginx curl && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+COPY --from=backend-build /app .
+COPY --from=frontend-build /app/dist /var/www/html
+
+RUN rm /etc/nginx/sites-enabled/default
+COPY nginx.conf /etc/nginx/sites-enabled/default
+
+RUN printf '#!/bin/bash\nnginx &\ncd /app && dotnet backend.dll\n' > /start.sh && chmod +x /start.sh
+
+EXPOSE 80
+HEALTHCHECK --interval=30s --timeout=5s --retries=3 --start-period=30s \
+  CMD ["curl", "-f", "http://localhost:80/health"]
+CMD ["/bin/bash", "/start.sh"]