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/wwwroot/css/app.css

@@ -0,0 +1,103 @@
+html, body {
+    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
+}
+
+h1:focus {
+    outline: none;
+}
+
+a, .btn-link {
+    color: #0071c1;
+}
+
+.btn-primary {
+    color: #fff;
+    background-color: #1b6ec2;
+    border-color: #1861ac;
+}
+
+.btn:focus, .btn:active:focus, .btn-link.nav-link:focus, .form-control:focus, .form-check-input:focus {
+  box-shadow: 0 0 0 0.1rem white, 0 0 0 0.25rem #258cfb;
+}
+
+.content {
+    padding-top: 1.1rem;
+}
+
+.valid.modified:not([type=checkbox]) {
+    outline: 1px solid #26b050;
+}
+
+.invalid {
+    outline: 1px solid red;
+}
+
+.validation-message {
+    color: red;
+}
+
+#blazor-error-ui {
+    background: lightyellow;
+    bottom: 0;
+    box-shadow: 0 -1px 2px rgba(0, 0, 0, 0.2);
+    display: none;
+    left: 0;
+    padding: 0.6rem 1.25rem 0.7rem 1.25rem;
+    position: fixed;
+    width: 100%;
+    z-index: 1000;
+}
+
+    #blazor-error-ui .dismiss {
+        cursor: pointer;
+        position: absolute;
+        right: 0.75rem;
+        top: 0.5rem;
+    }
+
+.blazor-error-boundary {
+    background: url(data:image/svg+xml;base64,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) no-repeat 1rem/1.8rem, #b32121;
+    padding: 1rem 1rem 1rem 3.7rem;
+    color: white;
+}
+
+    .blazor-error-boundary::after {
+        content: "An error has occurred."
+    }
+
+.loading-progress {
+    position: relative;
+    display: block;
+    width: 8rem;
+    height: 8rem;
+    margin: 20vh auto 1rem auto;
+}
+
+    .loading-progress circle {
+        fill: none;
+        stroke: #e0e0e0;
+        stroke-width: 0.6rem;
+        transform-origin: 50% 50%;
+        transform: rotate(-90deg);
+    }
+
+        .loading-progress circle:last-child {
+            stroke: #1b6ec2;
+            stroke-dasharray: calc(3.141 * var(--blazor-load-percentage, 0%) * 0.8), 500%;
+            transition: stroke-dasharray 0.05s ease-in-out;
+        }
+
+.loading-progress-text {
+    position: absolute;
+    text-align: center;
+    font-weight: bold;
+    inset: calc(20vh + 3.25rem) 0 auto 0.2rem;
+}
+
+    .loading-progress-text:after {
+        content: var(--blazor-load-percentage-text, "Loading");
+    }
+
+code {
+    color: #c02d76;
+}