style: format frontend, docs and skills with prettier; add .prettierignore

One-time prettier --write so the new format:check CI gate starts green.
.prettierignore excludes generated (api-client.ts, documentation.json),
vendored (public/cibg-huisstijl), and backend (dotnet format owns it).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/app/shared/ui/upload/document-upload/document-upload.component.ts

@@ -9,9 +9,15 @@ import { UploadStatusBannerComponent } from '../upload-status-banner/upload-stat
 @Component({
   selector: 'app-document-upload',
   imports: [DocumentCategoryComponent, UploadStatusBannerComponent],
-  styles: [`
-    :host { display: flex; flex-direction: column; gap: var(--rhc-space-max-xl); }
-  `],
+  styles: [
+    `
+      :host {
+        display: flex;
+        flex-direction: column;
+        gap: var(--rhc-space-max-xl);
+      }
+    `,
+  ],
   template: `
     @if (state().categoriesError) {
       <app-upload-status-banner type="error" [message]="state().categoriesError!" />
@@ -30,7 +36,8 @@ import { UploadStatusBannerComponent } from '../upload-status-banner/upload-stat
           (removeUpload)="removeUpload.emit($event)"
           (retryUpload)="retryUpload.emit($event)"
           (deleteUpload)="deleteUpload.emit($event)"
-          (channelChange)="channelChange.emit({ categoryId: c.categoryId, channel: $event })" />
+          (channelChange)="channelChange.emit({ categoryId: c.categoryId, channel: $event })"
+        />
       }
     }
   `,