Refactor DTOs, add Blazor WASM frontend, enable CORS

- Split `CatalogDto` into `CatalogReadDto` and `CatalogWriteDto` for clear separation of read/write operations in both backend and frontend.
- Updated API controllers, services, and AutoMapper profiles to use new DTOs; ensured audit fields are set in service layer.
- Enabled CORS in the API project to support Blazor WASM frontend.
- Added new Blazor WebAssembly project (`DbFirst.BlazorWasm`) with catalog management UI, API client, Bootstrap v5.1.0 styling, and configuration-driven API base URL.
- Included `bootstrap.min.css` and its source map for frontend styling and easier debugging.
- Updated solution file to include new project and support multiple build configurations.
- Result: improved API design, clean DTO separation, and a modern interactive frontend for catalog management.

DbFirst.BlazorWasm/Services/CatalogApiClient.cs

@@ -0,0 +1,49 @@
+using System.Net.Http.Json;
+using DbFirst.BlazorWasm.Models;
+
+namespace DbFirst.BlazorWasm.Services;
+
+public class CatalogApiClient
+{
+    private readonly HttpClient _httpClient;
+    private const string Endpoint = "api/catalogs";
+
+    public CatalogApiClient(HttpClient httpClient)
+    {
+        _httpClient = httpClient;
+    }
+
+    public async Task<List<CatalogReadDto>> GetAllAsync()
+    {
+        var result = await _httpClient.GetFromJsonAsync<List<CatalogReadDto>>(Endpoint);
+        return result ?? new List<CatalogReadDto>();
+    }
+
+    public async Task<CatalogReadDto?> GetByIdAsync(int id)
+    {
+        return await _httpClient.GetFromJsonAsync<CatalogReadDto>($"{Endpoint}/{id}");
+    }
+
+    public async Task<CatalogReadDto?> CreateAsync(CatalogWriteDto dto)
+    {
+        var response = await _httpClient.PostAsJsonAsync(Endpoint, dto);
+        if (!response.IsSuccessStatusCode)
+        {
+            return null;
+        }
+
+        return await response.Content.ReadFromJsonAsync<CatalogReadDto>();
+    }
+
+    public async Task<bool> UpdateAsync(int id, CatalogWriteDto dto)
+    {
+        var response = await _httpClient.PutAsJsonAsync($"{Endpoint}/{id}", dto);
+        return response.IsSuccessStatusCode;
+    }
+
+    public async Task<bool> DeleteAsync(int id)
+    {
+        var response = await _httpClient.DeleteAsync($"{Endpoint}/{id}");
+        return response.IsSuccessStatusCode;
+    }
+}