Fix Purchase Order modal and reorganize documentation

Frontend Changes:
- Fix runtime error: Remove undefined handleModify reference from ActionQueueCard in DashboardPage
- Migrate PurchaseOrderDetailsModal to use correct PurchaseOrderItem type from purchase_orders service
- Fix item display: Parse unit_price as string (Decimal) instead of number
- Use correct field names: item_notes instead of notes
- Remove deprecated PurchaseOrder types from suppliers.ts to prevent type conflicts
- Update CreatePurchaseOrderModal to use unified types
- Clean up API exports: Remove old PO hooks re-exported from suppliers
- Add comprehensive translations for PO modal (en, es, eu)

Documentation Reorganization:
- Move WhatsApp implementation docs to docs/03-features/notifications/whatsapp/
- Move forecast validation docs to docs/03-features/forecasting/
- Move specification docs to docs/03-features/specifications/
- Move deployment docs (Colima, K8s, VPS sizing) to docs/05-deployment/
- Archive completed implementation summaries to docs/archive/implementation-summaries/
- Delete obsolete FRONTEND_CHANGES_NEEDED.md
- Standardize filenames to lowercase with hyphens

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/locales/en/purchase_orders.json

@@ -3,13 +3,57 @@
   "purchase_orders": "Purchase Orders",
   "created": "Created",
   "supplier": "Supplier",
+  "supplier_name": "Supplier Name",
   "order_date": "Order Date",
   "expected_delivery": "Expected Delivery",
   "items": "Items",
   "no_items": "No items in this order",
   "notes": "Notes",
+  "order_notes": "Order Notes",
   "not_found": "Purchase order not found",
   "total_amount": "Total Amount",
+  "general_information": "General Information",
+  "financial_summary": "Financial Summary",
+  "dates": "Dates",
+  "po_number": "PO Number",
+  "status_label": "Status",
+  "quantity": "Quantity",
+  "unit_price": "Unit Price",
+  "quality_requirements": "Quality Requirements",
+  "total": "Total",
+  "priority": "Priority",
+  "required_delivery_date": "Required Delivery Date",
+  "supplier_info": "Supplier Information",
+  "order_details": "Order Details",
+  "products": "Products",
+  "modify_order": "Modify Purchase Order",
+  "modifying_order": "Modifying Order",
+  "supplier_cannot_modify": "Supplier cannot be modified",
+  "adjust_priority": "Adjust the priority of this order",
+  "delivery_deadline": "Delivery deadline",
+  "special_instructions": "Special instructions for supplier...",
+  "additional_info": "Additional information or special instructions",
+  "product": "Product",
+  "sku": "SKU",
+  "ordered_quantity": "Ordered Quantity",
+  "unit": "Unit",
+  "unit_price_euro": "Unit Price (€)",
+  "add_product": "Add Product",
+  "modify_quantities": "Modify quantities, units and prices as needed",
+  "at_least_one_product": "Please add at least one product",
+  "quantities_greater_zero": "All quantities must be greater than 0",
+  "products_need_names": "All products must have a name",
+  "priority_urgent": "Urgent",
+  "priority_high": "High",
+  "priority_normal": "Normal",
+  "priority_low": "Low",
+  "unit_kg": "Kilograms",
+  "unit_g": "Grams",
+  "unit_l": "Liters",
+  "unit_ml": "Milliliters",
+  "unit_units": "Units",
+  "unit_boxes": "Boxes",
+  "unit_bags": "Bags",
   "status": {
     "draft": "Draft",
     "pending_approval": "Pending Approval",
@@ -31,6 +75,8 @@
   "actions": {
     "approve": "Approve Order",
     "modify": "Modify Order",
-    "close": "Close"
+    "close": "Close",
+    "save": "Save Changes",
+    "cancel": "Cancel"
   }
 }