Fix multiple onboarding and navigation issues

**1. Remove duplicate navigation buttons in SetupWizard**
- Removed external navigation footer from SetupWizard (lines 370-383)
- All setup wizard steps now have only internal navigation buttons
- Prevents confusion with double Continue buttons in onboarding

**2. Fix quality template API call failure**
- Fixed userId validation in QualitySetupStep:17
- Changed from defaulting to empty string to undefined
- Added validation check before API call to prevent UUID errors
- Disabled submit button when userId not available
- Added error message display for missing user

Related: frontend/src/components/domain/setup-wizard/steps/QualitySetupStep.tsx:17,51-54,376

**3. Delete regular tours implementation (keep demo tour)**
Removed custom tours system while preserving demo tour functionality:
- Deleted TourContext.tsx and TourProvider
- Deleted Tour UI components folder
- Deleted tours/tours.ts definitions
- Deleted tour.json translations
- Removed TourProvider from App.tsx
- Removed TourButton from Sidebar

Demo tour (useDemoTour, driver.js) remains intact and functional.

Files deleted:
- frontend/src/contexts/TourContext.tsx
- frontend/src/components/ui/Tour/* (all files)
- frontend/src/tours/tours.ts
- frontend/src/locales/es/tour.json

**4. Issues verified/confirmed:**
- Quality type select UI already working (callback setState pattern)
- Inventory lots UI confirmed present in InventorySetupStep:683,788,833
- Lots UI visible after adding ingredients in onboarding flow

**Build Status:** ✓ All changes verified, build successful in 21.95s

frontend/src/locales/es/tour.json

@@ -1,41 +0,0 @@
-{
-  "step_progress": "Paso {{current}} de {{total}}",
-  "close": "Cerrar",
-  "previous": "Anterior",
-  "next": "Siguiente",
-  "finish": "Finalizar",
-  "skip": "Omitir tour",
-  "start_tour": "Iniciar tour",
-  "restart_tour": "Reiniciar tour",
-  "tours": {
-    "dashboard": {
-      "name": "Tour del Dashboard",
-      "description": "Conoce las funciones principales de tu dashboard"
-    },
-    "inventory": {
-      "name": "Tour de Inventario",
-      "description": "Aprende a gestionar tu inventario eficientemente"
-    },
-    "recipes": {
-      "name": "Tour de Recetas",
-      "description": "Descubre cómo crear y gestionar recetas"
-    },
-    "production": {
-      "name": "Tour de Producción",
-      "description": "Planifica tu producción con confianza"
-    },
-    "post_onboarding": {
-      "name": "Primeros Pasos",
-      "description": "Comienza a usar tu sistema de gestión"
-    }
-  },
-  "completed": {
-    "title": "¡Tour Completado!",
-    "message": "Has completado el tour de {{tourName}}",
-    "cta": "Entendido"
-  },
-  "trigger": {
-    "tooltip": "¿Necesitas ayuda? Inicia un tour guiado",
-    "button": "Tours Disponibles"
-  }
-}