Implement product variations, enhanced order workflow, mobile responsiveness, and product import system

## Product Variations System
- Add ProductVariation model with quantity-based pricing (1 for £10, 2 for £19, 3 for £25)
- Complete CRUD operations for product variations
- Enhanced ProductService to include variations in all queries
- Updated OrderItem to support ProductVariationId for variation-based orders
- Graceful error handling for duplicate quantity constraints
- Admin interface with variations management (Create/Edit/Delete)
- API endpoints for programmatic variation management

## Enhanced Order Workflow Management
- Redesigned OrderStatus enum with clear workflow states (Accept → Packing → Dispatched → Delivered)
- Added workflow tracking fields (AcceptedAt, PackingStartedAt, DispatchedAt, ExpectedDeliveryDate)
- User tracking for accountability (AcceptedByUser, PackedByUser, DispatchedByUser)
- Automatic delivery date calculation (dispatch date + working days, skips weekends)
- On Hold workflow for problem resolution with reason tracking
- Tab-based orders interface focused on workflow stages
- One-click workflow actions from list view

## Mobile-Responsive Design
- Responsive orders interface: tables on desktop, cards on mobile
- Touch-friendly buttons and spacing for mobile users
- Horizontal scrolling tabs with condensed labels on mobile
- Color-coded status borders for quick visual recognition
- Smart text switching based on screen size

## Product Import/Export System
- CSV import with product variations support
- Template download with examples
- Export existing products to CSV
- Detailed import results with success/error reporting
- Category name resolution (no need for GUIDs)
- Photo URLs import support

## Enhanced Dashboard
- Product variations count and metrics
- Stock alerts (low stock/out of stock warnings)
- Order workflow breakdown (pending, accepted, dispatched counts)
- Enhanced layout with more detailed information

## Technical Improvements
- Fixed form binding issues across all admin forms
- Removed external CDN dependencies for isolated deployment
- Bot Wizard form with auto-personality assignment
- Proper authentication scheme configuration (Cookie + JWT)
- Enhanced debug logging for troubleshooting

## Self-Contained Deployment
- All external CDN references replaced with local libraries
- Ready for air-gapped/isolated network deployment
- No external internet dependencies

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

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

LittleShop/Enums/OrderStatus.cs

@@ -2,12 +2,23 @@ namespace LittleShop.Enums;
 
 public enum OrderStatus
 {
+    // Initial states
     PendingPayment = 0,
     PaymentReceived = 1,
-    Processing = 2,
-    PickingAndPacking = 3,
-    Shipped = 4,
-    Delivered = 5,
-    Cancelled = 6,
-    Refunded = 7
+
+    // Workflow states
+    Accepted = 2,       // Order accepted by operator, ready for packing
+    Packing = 3,        // Currently being packed
+    Dispatched = 4,     // Shipped/dispatched to customer
+    Delivered = 5,      // Delivered to customer (auto-calculated)
+
+    // Side states
+    OnHold = 10,        // Order held for problem resolution
+    Cancelled = 11,     // Order cancelled
+    Refunded = 12,      // Order refunded
+
+    // Legacy states (for backward compatibility)
+    Processing = 20,         // Legacy: mapped to Accepted
+    PickingAndPacking = 21,  // Legacy: mapped to Packing
+    Shipped = 22             // Legacy: mapped to Dispatched
 }