Fix Releases tab naming, duplicate button, and approve/reject error feedback

Releases page:
- Rename "Pipeline" tab → "Releases" (first tab should match page name)
- Default activeTab from 'pipeline' → 'releases'
- Fix embedded ReleaseListComponent also clearing parent's pageAction on destroy

Deployments page:
- Approve/reject now show error banner when API fails instead of silently swallowing
  (the demo env returns 404 for approval endpoints, making buttons appear broken)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Web/StellaOps.Web/src/app/features/release-orchestrator/releases/release-list/release-list.component.ts

@@ -855,7 +855,9 @@ export class ReleaseListComponent implements OnInit, OnDestroy {
   }
 
   ngOnDestroy(): void {
-    this.pageAction.clear();
+    if (!this.embedded) {
+      this.pageAction.clear();
+    }
   }
 
   onSearchInput(event: Event): void {

src/Web/StellaOps.Web/src/app/features/releases/releases-activity.component.ts

@@ -787,7 +787,10 @@ export class ReleasesActivityComponent implements OnInit, OnDestroy {
     if (!apr) return;
     this.approvalApi.approve(apr.id, 'Approved from deployments page').pipe(take(1)).subscribe({
       next: () => { this.activeApr.set(null); this.loadPendingApprovals(); },
-      error: () => this.activeApr.set(null),
+      error: (err) => {
+        this.activeApr.set(null);
+        this.error.set(`Approve failed: ${err?.message || 'API unavailable'}`);
+      },
     });
   }
   onReject(apr: ApprovalRequest): void {
@@ -800,7 +803,11 @@ export class ReleasesActivityComponent implements OnInit, OnDestroy {
     if (!apr) return;
     this.approvalApi.reject(apr.id, this.rejectReason || 'Rejected from deployments page').pipe(take(1)).subscribe({
       next: () => { this.showRejectDlg.set(false); this.activeApr.set(null); this.loadPendingApprovals(); },
-      error: () => { this.showRejectDlg.set(false); this.activeApr.set(null); },
+      error: (err) => {
+        this.showRejectDlg.set(false);
+        this.activeApr.set(null);
+        this.error.set(`Reject failed: ${err?.message || 'API unavailable'}`);
+      },
     });
   }
   cancelReject(): void { this.showRejectDlg.set(false); this.activeApr.set(null); }

src/Web/StellaOps.Web/src/app/features/releases/releases-unified-page.component.ts

@@ -23,7 +23,7 @@ import { PlatformContextStore } from '../../core/context/platform-context.store'
 import type { ReleaseWorkflowStatus } from '../../core/api/release-management.models';
 
 const RELEASE_TABS: readonly StellaPageTab[] = [
-  { id: 'pipeline', label: 'Pipeline', icon: 'M21 16V8a2 2 0 0 0-1-1.73l-7-4a2 2 0 0 0-2 0l-7 4A2 2 0 0 0 3 8v8a2 2 0 0 0 1 1.73l7 4a2 2 0 0 0 2 0l7-4A2 2 0 0 0 21 16z' },
+  { id: 'releases', label: 'Releases', icon: 'M21 16V8a2 2 0 0 0-1-1.73l-7-4a2 2 0 0 0-2 0l-7 4A2 2 0 0 0 3 8v8a2 2 0 0 0 1 1.73l7 4a2 2 0 0 0 2 0l7-4A2 2 0 0 0 21 16z' },
   { id: 'versions', label: 'Versions', icon: 'M12 2L2 7l10 5 10-5-10-5zM2 17l10 5 10-5M2 12l10 5 10-5' },
 ];
 
@@ -78,7 +78,7 @@ export interface PipelineRelease {
       <stella-page-tabs [tabs]="releaseTabs" [activeTab]="activeTab()" urlParam="tab"
         (tabChange)="activeTab.set($event)" ariaLabel="Releases tabs" />
 
-      @if (activeTab() === 'pipeline') {
+      @if (activeTab() === 'releases') {
       <!-- Pipeline -->
           <div class="rup__filters">
             <div class="rup__search">
@@ -382,7 +382,7 @@ export class ReleasesUnifiedPageComponent implements OnInit, OnDestroy {
   private readonly route = inject(ActivatedRoute);
 
   readonly releaseTabs = RELEASE_TABS;
-  readonly activeTab = signal<string>(this.route.snapshot.queryParamMap.get('tab') || 'pipeline');
+  readonly activeTab = signal<string>(this.route.snapshot.queryParamMap.get('tab') || 'releases');
 
   ngOnInit(): void {
     this.pageAction.set({ label: 'New Release', route: '/releases/new' });