Remove BTCPay completely, integrate SilverPAY only, configure TeleBot with real token

- Removed all BTCPay references from services and configuration
- Implemented SilverPAY as sole payment provider (no fallback)
- Fixed JWT authentication with proper key length (256+ bits)
- Added UsersController with full CRUD operations
- Updated User model with Email and Role properties
- Configured TeleBot with real Telegram bot token
- Fixed launchSettings.json with JWT environment variable
- E2E tests passing for authentication, catalog, orders
- Payment creation pending SilverPAY server fix

🤖 Generated with Claude Code

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

LittleShop/Controllers/CatalogController.cs

@@ -39,28 +39,36 @@ public class CatalogController : ControllerBase
 
     [HttpGet("products")]
     public async Task<ActionResult<PagedResult<ProductDto>>> GetProducts(
-        [FromQuery] int pageNumber = 1, 
-        [FromQuery] int pageSize = 20, 
+        [FromQuery] int pageNumber = 1,
+        [FromQuery] int pageSize = 20,
         [FromQuery] Guid? categoryId = null)
     {
-        var allProducts = categoryId.HasValue 
-            ? await _productService.GetProductsByCategoryAsync(categoryId.Value)
-            : await _productService.GetAllProductsAsync();
-            
-        var productList = allProducts.ToList();
-        var totalCount = productList.Count;
-        var skip = (pageNumber - 1) * pageSize;
-        var pagedProducts = productList.Skip(skip).Take(pageSize).ToList();
-        
-        var result = new PagedResult<ProductDto>
+        try
         {
-            Items = pagedProducts,
-            TotalCount = totalCount,
-            PageNumber = pageNumber,
-            PageSize = pageSize
-        };
-            
-        return Ok(result);
+            var allProducts = categoryId.HasValue
+                ? await _productService.GetProductsByCategoryAsync(categoryId.Value)
+                : await _productService.GetAllProductsAsync();
+
+            var productList = allProducts.ToList();
+            var totalCount = productList.Count;
+            var skip = (pageNumber - 1) * pageSize;
+            var pagedProducts = productList.Skip(skip).Take(pageSize).ToList();
+
+            var result = new PagedResult<ProductDto>
+            {
+                Items = pagedProducts,
+                TotalCount = totalCount,
+                PageNumber = pageNumber,
+                PageSize = pageSize
+            };
+
+            return Ok(result);
+        }
+        catch (Exception ex)
+        {
+            // Log the error and return a proper error response
+            return StatusCode(500, new { message = "An error occurred while fetching products", error = ex.Message });
+        }
     }
 
     [HttpGet("products/{id}")]