feat: Complete InventoryWizard i18n translation with extended field support

Add comprehensive translation keys for all inventory wizard fields and complete
the InventoryWizard component translation from English/Spanish/Basque.

Translation additions (en/es/eu):
- Extended inventory.fields with 48 new field labels and placeholders:
  * Pricing fields (averageCost, standardCost, sellingPrice, minimumPrice)
  * Inventory management fields (lowStockThreshold, reorderPoint, etc.)
  * Product info fields (packageSize, shelfLifeDays, displayLifeHours, etc.)
  * Storage fields (storageInstructions, handlingInstructions, isPerishable)
  * Supplier fields (preferredSupplierId, supplierProductCode)
  * Quality fields (allergenInfo, nutritionalInfo, certifications)
  * Physical properties (weight, volume, dimensions, color)
  * Status tracking (isActive, trackByLot, trackByExpiry, allowNegativeStock)
  * Additional fields (notes, tags, customFields)

- Added ingredientCategories with 10 options (flour, dairy, eggs, fats, etc.)
- Added productCategories with 5 options (bread, pastry, cake, cookies, specialty)

InventoryWizard implementation:
- Translated all section headers (11 sections)
- Translated all field labels (58 fields)
- Translated all placeholder texts (35 placeholders)
- Translated all tooltips using tooltips namespace (11 tooltips)
- Translated ingredient and product category options (15 total)
- Translated wizard step title

Result: Fully internationalized InventoryWizard with complete en/es/eu support
covering all required fields, advanced options, and dynamic category selection.

frontend/src/locales/en/wizards.json

@@ -27,7 +27,55 @@
       "brand": "Brand",
       "brandPlaceholder": "Brand name",
       "description": "Description",
-      "descriptionPlaceholder": "Detailed description of the inventory item"
+      "descriptionPlaceholder": "Detailed description of the inventory item",
+      "averageCost": "Average Cost (€)",
+      "lastPurchasePrice": "Last Purchase Price (€)",
+      "standardCost": "Standard Cost (€)",
+      "sellingPrice": "Selling Price (€)",
+      "minimumPrice": "Minimum Price (€)",
+      "lowStockThreshold": "Low Stock Threshold",
+      "reorderPoint": "Reorder Point",
+      "reorderQuantity": "Reorder Quantity",
+      "maxStockLevel": "Max Stock Level",
+      "leadTimeDays": "Lead Time (days)",
+      "packageSize": "Package Size",
+      "packageSizePlaceholder": "E.g., 25kg bag, 12-pack",
+      "shelfLifeDays": "Shelf Life (days)",
+      "displayLifeHours": "Display Life (hours)",
+      "storageTempRange": "Storage Temp Range (°C)",
+      "storageTempMin": "Min",
+      "storageTempMax": "Max",
+      "storageInstructions": "Storage Instructions",
+      "storageInstructionsPlaceholder": "E.g., Store in cool, dry place away from direct sunlight",
+      "handlingInstructions": "Handling Instructions",
+      "handlingInstructionsPlaceholder": "Special handling requirements",
+      "isPerishable": "Perishable Item",
+      "preferredSupplierId": "Preferred Supplier ID",
+      "preferredSupplierIdPlaceholder": "Supplier ID",
+      "supplierProductCode": "Supplier Product Code",
+      "supplierProductCodePlaceholder": "Supplier's product code",
+      "allergenInfo": "Allergen Information",
+      "allergenInfoPlaceholder": "gluten, milk, eggs",
+      "nutritionalInfo": "Nutritional Information",
+      "nutritionalInfoPlaceholder": "calories:250, protein:8g, carbs:45g",
+      "certifications": "Certifications",
+      "certificationsPlaceholder": "Organic, Non-GMO, Kosher",
+      "weight": "Weight (kg)",
+      "volume": "Volume (L)",
+      "dimensions": "Dimensions (L×W×H cm)",
+      "dimensionsPlaceholder": "30×20×15",
+      "color": "Color",
+      "colorPlaceholder": "Product color",
+      "isActive": "Active Item",
+      "trackByLot": "Track by Lot/Batch",
+      "trackByExpiry": "Track by Expiry Date",
+      "allowNegativeStock": "Allow Negative Stock",
+      "notes": "Notes",
+      "notesPlaceholder": "Additional notes about this item",
+      "tags": "Tags",
+      "tagsPlaceholder": "organic, premium, seasonal",
+      "customFields": "Custom Fields (JSON)",
+      "customFieldsPlaceholder": "{\"custom_field\": \"value\"}"
     },
     "sections": {
       "basicInformation": "Basic Information",
@@ -59,6 +107,27 @@
       "dozen": "Dozen",
       "lb": "Pounds (lb)",
       "oz": "Ounces (oz)"
+    },
+    "ingredientCategories": {
+      "select": "Select...",
+      "flour": "Flours",
+      "dairy": "Dairy",
+      "eggs": "Eggs",
+      "fats": "Fats & Oils",
+      "sweeteners": "Sweeteners",
+      "additives": "Additives",
+      "fruits": "Fruits",
+      "nuts": "Nuts & Seeds",
+      "spices": "Spices",
+      "leavening": "Leavening Agents"
+    },
+    "productCategories": {
+      "select": "Select...",
+      "bread": "Bread",
+      "pastry": "Pastry",
+      "cake": "Cakes",
+      "cookies": "Cookies",
+      "specialty": "Specialty Items"
     }
   },
   "qualityTemplate": {