style: format the repo with prettier (green format:check)

`npm run format:check` (a CI gate) had drifted red across 44 files — pre-existing
files plus recently-added ones committed without formatting. Ran `prettier --write .`;
no logic changes. Also regenerates documentation.json (compodoc reflects the reformatted
component sources).

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

src/app/brief/ui/letter-canvas/letter-canvas.component.ts

@@ -178,7 +178,9 @@ const A4_HEIGHT_PX = (297 * 96) / 25.4;
             (click)="zoomBy(0.1)"
             >+</app-button
           >
-          <app-button variant="subtle" (click)="zoomLevel.set(1)">{{ zoomResetLabel() }}</app-button>
+          <app-button variant="subtle" (click)="zoomLevel.set(1)">{{
+            zoomResetLabel()
+          }}</app-button>
         </div>
         @if (editableRegions() === 'none') {
           <app-button
@@ -399,7 +401,10 @@ export class LetterCanvasComponent {
   protected editing = computed(() => this.editableRegions() === 'template');
 
   protected emitEdit(field: OrgTemplateTextField, event: Event) {
-    this.templateEdit.emit({ field, value: (event.target as HTMLInputElement | HTMLTextAreaElement).value });
+    this.templateEdit.emit({
+      field,
+      value: (event.target as HTMLInputElement | HTMLTextAreaElement).value,
+    });
   }
 
   protected marginStyle = computed(() => {