Mijn aanvragen (F2): document preview/download on completed uploads

Re-opening a Concept wizard now lets the user preview/download what they already
uploaded (PRD 0001 goal 2).

- document-chip: optional previewUrl input → a "Voorbeeld / Download" link (opens
  the stored bytes; server serves inline for pdf/image, attachment otherwise).
- previewUrlFor callback threaded document-upload → document-category → single-upload
  (which builds the URL from a completed upload's documentId). Keeps URL-building out
  of the presentational atoms.
- registratie + herregistratie wizards supply previewUrlFor via UploadAdapter.contentUrl,
  returning undefined for dev-simulation `demo-*` ids (no stored bytes → no link).
- Story: DocumentChip/WithPreview.

Gates green: vitest 128, lint, ng build, check:tokens; backend dotnet 56.
(build-storybook has a pre-existing Compodoc/$localize issue in untouched files.)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/app/herregistratie/ui/herregistratie-wizard/herregistratie-wizard.component.ts

@@ -11,6 +11,7 @@ import { WizardState, WizardMsg, Draft, initial, reduce, hasProgress } from '@he
 import { createDraftSync } from '@registratie/application/draft-sync';
 import { DocumentUploadComponent } from '@shared/ui/upload/document-upload/document-upload.component';
 import { createUploadController } from '@shared/upload/upload-controller';
+import { UploadAdapter } from '@shared/upload/upload.adapter';
 import { UploadState, initialUpload, deliveryRefs } from '@shared/upload/upload.machine';
 
 /** Organism: multi-step herregistratie wizard. ALL state lives in one signal
@@ -57,6 +58,7 @@ import { UploadState, initialUpload, deliveryRefs } from '@shared/upload/upload.
         @case (3) {
           <app-document-upload
             [state]="upload()"
+            [previewUrlFor]="previewUrlFor"
             (fileSelected)="uploadCtl.onFileSelected($event.categoryId, $event.files)"
             (removeUpload)="uploadCtl.onRemove($event)"
             (retryUpload)="uploadCtl.onRetry($event)"
@@ -76,8 +78,14 @@ import { UploadState, initialUpload, deliveryRefs } from '@shared/upload/upload.
 })
 export class HerregistratieWizardComponent {
   private profile = inject(BigProfileStore);
+  private uploadAdapter = inject(UploadAdapter);
   private store = createStore<WizardState, WizardMsg>(initial, reduce);
 
+  /** Preview/download link for a completed upload; dev-simulation `demo-*` ids have
+      no stored bytes, so they get no link. */
+  protected previewUrlFor = (documentId: string): string | undefined =>
+    documentId.startsWith('demo-') ? undefined : this.uploadAdapter.contentUrl(documentId);
+
   /** Optional seed so Storybook / the showcase can mount any state directly. */
   seed = input<WizardState>(initial);