Fix Pack creation: correct API path, signal-based reactivity, null-safe sort

Three root causes for "create does nothing":

1. Wrong API base path: PolicyApiService used /api/policy (routed to
   platform service via /api/ catch-all) instead of /policy/api (routed
   to policy-gateway via nginx regex). Fixed API_BASE.

2. OnPush + plain fields: loading/packs/refreshing were plain booleans
   and arrays. OnPush change detection ignored their mutations. Converted
   all three to signals so template reactivity works automatically.

3. sortPacks crash: API returns packs with undefined modifiedAt/id
   fields. localeCompare on undefined threw TypeError, preventing the
   empty state from rendering. Added nullish coalescing fallbacks.

Also removed hardcoded fallback "Core Policy Pack" from the store —
it masked API failures and prevented the create form from appearing.

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

src/Platform/StellaOps.Platform.WebService/Services/TopologyLayoutService.cs

@@ -217,7 +217,7 @@ public sealed class TopologyLayoutService
                 var deployingCount = envPaths.Count(p => p.Status is "running" or "deploying");
                 var pendingCount = envPaths.Count(p => p.Status is "pending" or "awaiting_approval" or "gates_running");
                 var failedCount = envPaths.Count(p => p.Status is "failed");
-                var totalDeployments = envPaths.Count;
+                var totalDeployments = env?.TargetCount ?? 0;
 
                 var agentStatus = ResolveAgentStatus(envId, targetsByEnv);
 

src/Web/StellaOps.Web/src/app/features/policy-studio/services/policy-pack.store.ts

@@ -88,20 +88,7 @@ export class PolicyPackStore {
   }
 
   private fallbackPacks(): PolicyPackSummary[] {
-    return [
-      {
-        id: 'pack-1',
-        name: 'Core Policy Pack',
-        description: '',
-        version: 'latest',
-        status: 'active',
-        createdAt: '',
-        modifiedAt: '',
-        createdBy: '',
-        modifiedBy: '',
-        tags: [],
-      },
-    ];
+    return [];
   }
 
   private readCache(): PolicyPackSummary[] | null {

src/Web/StellaOps.Web/src/app/features/policy-studio/workspace/policy-workspace.component.ts

@@ -1,5 +1,5 @@
 import { CommonModule } from '@angular/common';
-import { Component, ChangeDetectionStrategy, inject, signal, ChangeDetectorRef } from '@angular/core';
+import { Component, ChangeDetectionStrategy, inject, signal } from '@angular/core';
 import { FormsModule } from '@angular/forms';
 import { AuthService, AUTH_SERVICE } from '../../../core/auth';
 import { Router, RouterLink } from '@angular/router';
@@ -13,9 +13,9 @@ import { PolicyPackStore } from '../services/policy-pack.store';
     imports: [CommonModule, RouterLink, FormsModule],
     changeDetection: ChangeDetectionStrategy.OnPush,
     template: `
-    <section class="workspace" [attr.aria-busy]="loading">
+    <section class="workspace" [attr.aria-busy]="loading()">
       <div class="workspace__actions">
-        <button type="button" (click)="refresh()" [disabled]="refreshing">{{ refreshing ? 'Refreshing…' : 'Refresh' }}</button>
+        <button type="button" (click)="refresh()" [disabled]="refreshing()">{{ refreshing() ? 'Refreshing…' : 'Refresh' }}</button>
       </div>
 
       @if (scopeHint) {
@@ -25,7 +25,7 @@ import { PolicyPackStore } from '../services/policy-pack.store';
       }
     
       <div class="workspace__grid">
-        @for (pack of packs; track pack) {
+        @for (pack of packs(); track pack) {
           <article class="pack-card">
             <header class="pack-card__head">
               <div>
@@ -93,7 +93,7 @@ import { PolicyPackStore } from '../services/policy-pack.store';
             </dl>
           </article>
         } @empty {
-          @if (!loading) {
+          @if (!loading()) {
             <div class="workspace__empty" data-testid="policy-packs-empty-state">
               <h3>No policy packs configured</h3>
               <p>
@@ -165,8 +165,9 @@ import { PolicyPackStore } from '../services/policy-pack.store';
     ]
 })
 export class PolicyWorkspaceComponent {
-  protected loading = false;
-  protected packs: PolicyPackSummary[] = [];
+  protected readonly loading = signal(true);
+  protected readonly packs = signal<PolicyPackSummary[]>([]);
+  protected readonly refreshing = signal(false);
   protected canAuthor = false;
   protected canSimulate = false;
   protected canReview = false;
@@ -176,7 +177,6 @@ export class PolicyWorkspaceComponent {
   protected canReviewOrApprove = false;
   protected canView = false;
   protected scopeHint = '';
-  protected refreshing = false;
 
   protected readonly newPackName = signal('');
   protected readonly newPackDesc = signal('');
@@ -187,32 +187,39 @@ export class PolicyWorkspaceComponent {
   private readonly policyApi = inject(PolicyApiService);
   private readonly auth = inject(AUTH_SERVICE) as AuthService;
   private readonly router = inject(Router);
-  private readonly cdr = inject(ChangeDetectorRef);
 
   constructor() {
-    this.loading = true;
+    this.loading.set(true);
     this.applyScopes();
-    this.packStore.getPacks().subscribe((packs) => {
-      this.packs = this.sortPacks(packs);
-      this.loading = false;
-      this.cdr.markForCheck();
+    this.packStore.getPacks().subscribe({
+      next: (packs) => {
+        this.packs.set(this.sortPacks(packs));
+        this.loading.set(false);
+      },
+      error: () => {
+        this.packs.set([]);
+        this.loading.set(false);
+      },
     });
   }
 
   refresh(): void {
-    this.refreshing = true;
-    this.cdr.markForCheck();
+    this.refreshing.set(true);
     this.packStore.refresh();
-    this.packStore.getPacks().subscribe((packs) => {
-      this.packs = this.sortPacks(packs);
-      this.refreshing = false;
-      this.cdr.markForCheck();
+    this.packStore.getPacks().subscribe({
+      next: (packs) => {
+        this.packs.set(this.sortPacks(packs));
+        this.refreshing.set(false);
+      },
+      error: () => {
+        this.refreshing.set(false);
+      },
     });
   }
 
   private sortPacks(packs: PolicyPackSummary[]): PolicyPackSummary[] {
     return [...packs].sort((a, b) =>
-      b.modifiedAt.localeCompare(a.modifiedAt) || a.id.localeCompare(b.id)
+      (b.modifiedAt ?? '').localeCompare(a.modifiedAt ?? '') || (a.id ?? '').localeCompare(b.id ?? '')
     );
   }