style(ui): full UX/UI + motion pass across storefront, admin, editor

- fix save-bar buttons to use shared app-button primitive (were unstyled)
- fix platform-nav-group border/radius via structural selectors, drop dead
  -middle/-right classes
- storefront widgets (hero/categories/product-carousel/footer-nav): design
  tokens, hover/focus states, 44px touch targets, entrance motion, reduced-
  motion guards
- admin dashboard cards + quick-actions: hover lift, entrance animation
- admin product-form gallery remove badge: hover/focus + expanded hit area
- project-editor section.shared button styles: hover/active/focus/disabled
  states + reduced-motion; section-switch fade-in motion

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

src/app/widgets/ui/product-carousel-widget.component.ts

@@ -11,7 +11,7 @@ import { ProductCollectionWidgetData } from '../contracts/widget-data.contract';
   template: `
     <section class="product-carousel-widget">
       @if (data?.title) {
-        <h2>{{ data?.title }}</h2>
+        <h2 class="product-carousel-widget__title">{{ data?.title }}</h2>
       }
 
       @if (data?.products?.length) {
@@ -23,7 +23,15 @@ import { ProductCollectionWidgetData } from '../contracts/widget-data.contract';
   `,
   styles: [
     `
-      .product-carousel-widget { display: grid; gap: 1rem; }
+      .product-carousel-widget { display: grid; gap: var(--space-lg, 24px); }
+
+      .product-carousel-widget__title {
+        margin: 0;
+        font-size: 1.75rem;
+        font-weight: 700;
+        color: var(--text-primary, #1e3c38);
+      }
+
       .product-carousel-widget__empty { margin: 0; color: var(--text-secondary, #667a77); }
     `
   ],