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>

.gitignore

@@ -0,0 +1,25 @@
+# .NET
+bin/
+obj/
+*.user
+*.suo
+appsettings.*.local.json
+
+# Node/Bun
+node_modules/
+frontend/dist/
+frontend/.vite/
+
+# IDE
+.vs/
+.vscode/
+.idea/
+*.swp
+
+# OS
+.DS_Store
+Thumbs.db
+
+# Env
+.env
+.env.local