feat(portal-frontend): implement case-actions component

Renders record-assessment as a link only in redirect mode (otherwise
a form-trigger slot, filled in once record-assessment-form exists),
and take-ownership/release-ownership buttons purely off presence of
their optional action key. Emits requests upward rather than calling
the API itself - the actual take/release-ownership handling lands in
a later commit.

portal-frontend/src/app/case-detail/case-actions/case-actions.html

@@ -1 +1,19 @@
-<p>case-actions works!</p>
+@if (actions().recordAssessment.mode === 'redirect') {
+  <a data-testid="record-assessment-link" [href]="actions().recordAssessment.href">Beoordeling vastleggen (in legacy)</a>
+} @else {
+  <div data-testid="record-assessment-form">
+    <!-- app-record-assessment-form is embedded here once it exists -->
+  </div>
+}
+
+@if (actions().takeOwnership; as takeOwnership) {
+  <button type="button" data-testid="take-ownership-button" (click)="takeOwnershipRequested.emit(takeOwnership)">
+    In eigen beheer nemen
+  </button>
+}
+
+@if (actions().releaseOwnership; as releaseOwnership) {
+  <button type="button" data-testid="release-ownership-button" (click)="releaseOwnershipRequested.emit(releaseOwnership)">
+    Eigenaarschap teruggeven
+  </button>
+}

portal-frontend/src/app/case-detail/case-actions/case-actions.ts

@@ -1,6 +1,6 @@
-import { Component, input } from '@angular/core';
+import { Component, input, output } from '@angular/core';
 
-import { CaseDetailActions } from '../case-detail.types';
+import { ActionLink, CaseDetailActions } from '../case-detail.types';
 
 @Component({
   selector: 'app-case-actions',
@@ -10,4 +10,7 @@ import { CaseDetailActions } from '../case-detail.types';
 })
 export class CaseActions {
   readonly actions = input.required<CaseDetailActions>();
+
+  readonly takeOwnershipRequested = output<ActionLink>();
+  readonly releaseOwnershipRequested = output<ActionLink>();
 }